Preparation of 4-substituted but-3-ene-1-carboxylic acids and their esters
The present invention relates to a novel process for the preparation of 4-substituted but-3-ene-1-carboxylic acids or their esters of the general formula I ##STR1## where R 1  is an organic radical, R 2  is hydrogen or an organic radical, and R 1  and R 2  may furthermore be bonded to one another to form a 5-membered to 20-membered ring and should be inert under the reaction conditions described below, and R 3  is hydrogen or lower alkyl. 
     Tsuji et al., in J. Am. Chem. Soc. 86 (1964), 4350-4353, disclose that ethyl pent-3-ene-1-carboxylate (I, where R 1  is Me, R 2  is H and R 3  is Et) can be prepared by carbonylation of but-1-en-3-ol with carbon monoxide and ethanol in the presence of palladium chloride as a carbonylation catalyst. However, the yield of only 39% achieved in this procedure is unsatisfactory for industrial purposes. 
     Furthermore, Bittler et al., in Angew. Chemie, 80 (1968), 352-359, disclose that allyl alcohol and methanol can be carbonylated using a palladium chloride/triphenylphosphine complex to give methyl but-3-enecarboxylate in 65% yield. According to the authors (cf. loc cit, page 355), the carbonylation of the allyl alcohol takes place with retention of the double bond, so that the 4-substituted but-3-enecarboxylates have to be prepared using, as starting materials, the allyl alcohols ##STR2## which are difficult to obtain. 
     It is an object of the present invention to make the compounds I more readily accessible, these compounds generally being important for organic syntheses, and some of them being directly useful as fragrance materials. 
     We have found, unexpectedly in view of the work by Bittler et al., that this object is achieved by a process for the preparation of the compounds (I) defined at the outset, by carbonylation of a derivative of allyl alcohol with the aid of a palladium halide, wherein an allyl alcohol II ##STR3## is carbonylated with carbon monoxide at 50°-150° C. and under 200-700 bar, 
     (a) together with an alcohol III 
     
         R.sup.3&#39; --OH                                              (III) 
    
     where R 3&#39;   is lower alkyl, if a predominant amount of an ester I is to be prepared, or 
     (b) without a further reactant where an acid I is to be prepared, in the presence of an effective amount of a complex of a palladium halide and a tertiary phosphine (IV). 
     The starting compounds II are obtainable in a simple manner from the corresponding carbonyl compounds R 1  --CO--R 2  and vinyl magnesium halides. II can also be prepared from the carbonyl compounds and acetylides, such as sodium acetylide, with subsequent partial hydrogenation of the ethynyl group to the vinyl group. 
     On the basis of the very extensive investigations carried out to date, the nature of the compounds II, ie. the type of organic radicals R 1  and R 2 , is in principle unimportant with regard to the novel process, provided that these radicals do not contain any substituents or groups which are reactive under the carbonylation conditions. Examples of such reactive radicals are alkenyl groups having terminal double bonds; if, on the other hand, the double bond is an internal one, it is as a rule virtually never attacked under the reaction conditions. 
     Examples of suitable radicals R 1  and R 2  are aliphatic radicals of 1 to 30 carbon atoms, cycloaliphatic radicals having 3 to 12 ring members, aromatic radicals possessing from 1 to 3 isocyclic or heterocyclic aromatic rings, mixed radicals containing aliphatic and/or cycloaliphatic and/or aromatic groups in any sequence, and cyclic radicals which have from 3 to 20 ring members, are formed by R 1  and R 2  together and can in turn be substituted by the above radicals. 
     All of these radicals can furthermore contain substituents such as halogen, eg. fluorine or chlorine, hydroxyl (which in general is virtually never attacked during the carbonylation according to the invention), substituted amino, cyano, nitro, alkoxy, acyl, acyloxy, carbalkoxy, thiol, mercaptan, carboxamide or alkylsulfonyl. Particularly important alcohols II are those whose molecule contains one or more isoprene skeletons; the compounds I derived from these are often typical fragrance materials. 
     Suitable alcohols III are mainly lower alcohols, such as methanol and ethanol, since the carbonylation proceeds most rapidly with these. Higher alcohols of not more than about 6 carbon atoms can in principle also be used, although it is frequently more advantageous to introduce these into the molecule by transesterification of the methyl or ethyl esters I. 
     In general, it is preferable to use a molar excess of the alcohol III over the alcohol II. Usually, the molar ratio of III to II is from 2:1 to 6:1. If III is used as a solvent, this ratio may also be higher. 
     If the procedure is carried out in the absence of a further reactant, ie. without an alcohol III, the acids I are obtained. Predominant amounts of acid are also generally obtained when a tertiary alcohol III, eg. tert.-butanol, is used. 
     The carbonylation catalysts are complexes of a palladium halide, eg. the bromide or in particular the chloride, and a tertiary organic phosphine (IV). Since formation of these complexes takes place directly under the reaction conditions, the said complexes are advantageously employed in the form of their components; however, it is of course also possible to start from the preprepared complexes, eg. Pd(PPh 3 ) 2  Cl 2  (Ph=phenyl). 
     The tertiary phosphines IV are of the general formula IV ##STR4## where R 4 , R 5  and R 6  are each an organic radical. 
     In particular, R 4 , R 5  and R 6  can each be alkyl of 4 to 18 carbon atoms, C 1  -C 4  -alkylphenyl or, especially, phenyl. Two of these radicals may furthermore be bonded to one another to form a 5-membered to 8-membered ring, and it is of course also possible to use compounds possessing 2 or more tertiary phosphine groups, eg. 1,2-bis-(diphenylphosphino)-ethane. 
     The type of phosphines is in principle unimportant, so that it is in general preferable to use the cheapest member of this class of substances, ie. triphenylphosphine. 
     It is also advantageous to carry out the reaction in the presence of free phosphine, ie. phosphine which is not bonded in a complex. The preferred molar ratio of phosphine to Pd is from 3:1 to 10:1. 
     It is not possible to state a particular value for the effective amount of the catalyst because the reaction takes place in principle with infinitely small amounts of Pd, but is of course then very slow, and because large amounts have no adverse effect. Hence, the amount of Pd depends on the reactivity of the alcohol II and on the reaction time desired. In general, the amount of Pd is from 0.1 to 5 g per mole of II. 
     According to the general principles of process engineering, the reaction takes place most readily and most rapidly in the substantially homogeneous liquid phase. In general, homogeneity results automatically under the reaction conditions owing to the presence of the alcohol III, so that an additional solvent need not be used. If, however, the alcohol II is sparingly soluble, it is advisable to use a solvent, such as toluene, diethyl ether or tetrahydrofuran. 
     The pressure, which for the most part corresponds to the CO partial pressure, is in general from 100 to 650, in particular from 300 to 600, bar, and the recommended temperature is from 50° to 150° C., preferably from 90° to 110° C. Under these conditions, and using the recommended amounts of catalyst, the reaction times are about 1-24 hours. 
     The novel process can be carried out continuously or batchwise, and the method used is identical to the conventional carbonylation technique, so that more detailed description of this can be dispensed with. The same applies to the working up of the reaction mixtures. Owing to the sensitivity of the phosphines to oxidation, it is advisable to carry out the procedure in the absence of atmospheric oxygen. 
     When the alcohol III is also used, the products obtained are mainly the esters I, the free acids 1 also resulting; tertiary alcohols III generally give larger amounts of the acid. The amount of by-products is low in every case, although it was expected that the alcohols II would be dehydrated under the reaction conditions. The compounds I can be formed in the cis or trans form, predominant amounts of the trans isomer usually being obtained. 
    
    
     EXAMPLES 
     Various alcohols II were reacted with various alcohols III, in each case in the absence of atmospheric oxygen, at 100° C., in the presence of palladium chloride and triphenylphosphine (Pph 3 ), to give the acids or esters I. 
     Details of the other reaction conditions and of the results of the experiments are shown in the Table below. About 98% of the stated pressure is due to the CO partial pressure. Each of the reactions was terminated when scarcely any further CO was consumed. 
     The products were identified by means of gas chromatographic, H--NMR,  13  C--NMR, mass spectroscopic and IR analysis. The yields were determined gravimetrically; where separation into the acid and the ester presented difficulties, only the sum of the yields was determined. Boiling points and melting points are stated wherever they were obtained directly from the experiments. 
     
         __________________________________________________________________________
                             Pres-   Yields acid/ester I                  
Ex- Alcohol II   Alcohol III                                              
                        PdCl.sub.2 [g]                                    
                             sure                                         
                                Duration                                  
                                     Total yield, trans/cis ratio q       
ample                                                                     
    [g]          [g]    PPh.sub.3 [g]                                     
                             [bar]                                        
                                [h]  Characteristics                      
__________________________________________________________________________
 1  Pent-1-en-3-ol                                                        
                 MeOH   1.0  600                                          
                                17   14%                                  
                                        hex-3-enoic acid                  
    100          50     3.0          78%                                  
                                        methyl hex-3-enoate, bp.          
                                        100-101° C./               
                                     92%                                  
                                        q = 85:15 231 mbar                
 2  Hex-1-en-3-ol                                                         
                 EtOH   1.0  600                                          
                                 8   15%                                  
                                        hept-3-enoic acid                 
    100          50     3.0          54%                                  
                                        ethyl hept-3-enoate, bp.          
                                        89° C./45 mbar             
                                     69%                                  
                                        q = 85:15                         
                                        scent, acid: greenish, fruity,    
                                        some-                             
                                        what pungent                      
                                        ester: sweetish, floral,          
                                        somewhat                          
                                        tonka-like                        
 3  Hept-1-en-3-ol                                                        
                 EtOH   5.0  300                                          
                                15   18%                                  
                                        oct-3-enoic acid                  
    920          500    1.5          69%                                  
                                        ethyl oct-3-enoate, bp.           
                                        112-114° C./               
                                     87%                                  
                                        q = 80:20 54 mbar                 
                                        scent, acid and ester: greenish,  
                                        slightly fatty                    
 4  Oct-1-en-3-ol                                                         
                 n-propanol                                               
                        5.0  300                                          
                                 8   15%                                  
                                        non-3-enoic acid                  
    730          500    15.0         64%                                  
                                        n-propyl non-3-enoate, bp.        
                                        70-72° C./                 
                                     79%                                  
                                        q = 82:18 4 mbar                  
                                        scent, ester: green, slightly     
                                        herbaceous, fungal                
 5  3-Methylbut-1-en-3-ol                                                 
                 MeOH   2.5  300                                          
                                 8    9%                                  
                                        4-methylpent-3-enoic acid, bp.    
                                        122° C./                   
    1,000        500    7.5          47%                                  
                                        48 mbar                           
                                     56%                                  
                                        methyl 4-methylpent-3-enoate,     
                                        bp. 110° C./150 mbar       
 6  3,7-Dimethyloct-1-en-3-ol                                             
                 i-propanol                                               
                        2.5  300                                          
                                 8   23%                                  
                                        4,8-dimethylnon-3-enoic acid,     
    1,000        500    7.5          57%                                  
                                        bp. 165° C./45 mbar        
                                     80%                                  
                                        isopropyl 4,8-dimethylnon-3-enoate
                                        ,                                 
                                        bp. 145° C./37 mbar        
                                        q =  87:13                        
 7  3,7-Dimethyloct-1-en-3-ol                                             
                 n-propanol                                               
                        5    300                                          
                                 8   13%                                  
                                        4,8-Dimethylnon-3-enoic acid      
    1,000        500    15           68%                                  
                                        n-propyl 4,8-dimethylnon-3-enoate,
                                        3                                 
                                     81%                                  
                                        bp. 147° C./34 mbar        
                                        cis-ester: sweetish, balsamic,    
                                        fruity                            
                                        trans-ester: floral, somewhat     
                                        fatty                             
 8  3,7-Dimethyloct-1-en-3-ol                                             
                 n-butanol                                                
                        5    300                                          
                                15   17%                                  
                                        4,8-dimethylnon-3-enoic acid      
    1,000        5,000  15           63%                                  
                                        n-butyl 4,8-dimethylnon-3-enoate, 
                                        .                                 
                                     80%                                  
                                        bp. 160° C./37 mbar        
                                        q = 66:34                         
 9  3,7-Dimethylocta-1,6-                                                 
                 EtOH   5    250                                          
                                14   22%                                  
                                        4,8-dimethylnona-3,7-dienoic      
                                        acid                              
    dien-3-ol    500    15           61%                                  
                                        ethyl 4,8-dimethylnona-3,7-dienoat
                                        e                                 
    1,000                            83%                                  
                                        bp. 82-84° C./4 mbar       
                                        q = 68:32                         
                                        cis-ester: fruity, greenish       
                                        trans-ester: pleasantly fruity,   
                                        musk-like                         
10  3,7-Dimethylocta-1,6-                                                 
                 EtOH   2.5  300                                          
                                10   34%                                  
                                        4,8-dimethylnona-3,7-dienoic      
                                        acid                              
    dien-3-ol    500    7.5          56%                                  
                                        ethyl 4,8-dimethylnona-3,7-dienoat
                                        e                                 
    1,000                            90%                                  
                                        bp. 82° C./4 mbar          
11  3,7,11-Trimethyldodec-                                                
                 EtOH   2.5  300                                          
                                 6    3%                                  
                                        4,8,12-trimethyltridec-3-enoic    
                                        acid                              
    1-en-3-ol    205    7.5          90%                                  
                                        ethyl 4,8,12-trimethyltridec-3-eno
                                        ate                               
    410                              93%                                  
                                        bp. 125-130° C./4 mbar     
                                        q = 80:20                         
12  3,7,11-Trimethyldodeca-                                               
                 MeOH   2.5  300                                          
                                 6   11%                                  
                                        4,8,12-trimethyltrideca-3,7-dienoi
                                        c                                 
    1,6-dien-3-ol                                                         
                 500    7.5          63%                                  
                                        acid                              
    (dihydronerolidol)               74%                                  
                                        methyl 4,8,12-trimethyltrideca-3,7
                                        -                                 
    1,125                               dienoate, bp. 125-129°     
                                        C./4 mbar                         
13  3,7,11-Trimethyl-dodeca-                                              
                 EtOH   5    300                                          
                                 8    6%                                  
                                        4,8,12-trimethyltrideca-3,7-dienoi
                                        c                                 
    1,6-dien-3-ol                                                         
                 500    15           81%                                  
                                        acid                              
    (dihydronerolidol)               87%                                  
                                        ethyl 4,8,12-trimethyltrideca-3,7-
    1,000                               dienoate                          
14  3,7,11-Trimethyl-dodeca-                                              
                 MeOH   2.5  300                                          
                                10    7%                                  
                                        4,8,12-trimethyltrideca-3,7,11-   
    1,6,10-trien-3-ol                                                     
                 500    7.5          79%                                  
                                        trienoic acid                     
    (nerolidol)                      86%                                  
                                        methyl 4,8,12-trimethyltrideca-   
    1,000                               3,7,11-trienoate,                 
                                        bp. 129-130° C./4 mbar     
15  3,7,11-Trimethyl-dodeca-                                              
                 EtOH   2.5  300                                          
                                14    7%                                  
                                        4,8,12-trimethyltrideca-3,7,11-   
    1,6,10-trien-3-ol                                                     
                 500    7.5          79%                                  
                                        trienoic acid                     
    (nerolidol)                      86%                                  
                                        ethyl 4,8,12-trimethyltrideca-3,7,
                                        11-                               
    1,000                               trienoate, bp. 126-130°    
                                        C./4 mbar                         
16  3,7,11-Trimethyl-dodeca-                                              
                 EtOH   1.25 300                                          
                                17    9%                                  
                                        4,8,12-trimethyltrideca-3,7,11-   
    1,6,10-trien-3-ol                                                     
                 500    3.75         69%                                  
                                        trienoic acid                     
    (nerolidol)                      77%                                  
                                        ethyl 4,8,12-trimethyltrideca-3,7,
                                        11-                               
    1,000                               trienoate, bp. 127-152°    
                                        C./4 mbar                         
17  3,7,11,15-Tetramethyl-                                                
                 EtOH   2.5  300                                          
                                19    4%                                  
                                        4,8,12,16-tetramethylheptadec-3-  
    hexadec-1-en-3-ol                                                     
                 500    7.5          90%                                  
                                        enoic acid                        
    (isophytol)                      94%                                  
                                        ethyl 4,8,12,16-tetramethylheptade
                                        c-                                
    1,000                               3-enoate, bp. 162-167°     
                                        C./4 mbar                         
                                        q = 3:1                           
18  5-(2,6,6-Trimethylcyclo-                                              
                 EtOH   3.5  300                                          
                                 4    8%                                  
                                        6-(2,6,6-trimethylcyclohex-1-yl)-4
                                        -                                 
    hex-1-en-1-yl)-3-methyl-                                              
                 300    10.0            methylhex-3-enoic acid            
    pent-1-en-3-ol                   76%                                  
                                        ethyl 6-(2,6,6-trimethylcyclohex-1
                                        -                                 
    600                              84%                                  
                                        yl)-4-methylhex-3-enoate,         
                                        bp. 148-157° C./5 mbar     
                                        q = 82:18                         
                                        cis-ester: sweet fruity (apple,   
                                        strawberry)                       
19  5-(2,6,6-Trimethylcyclo-                                              
                 EtOH   1.0  600                                          
                                10   *  6-(2,6,6-trimethylcyclohex-1-enyl)
                                        -                                 
    hex-1-en-1-yl)-3-methyl-                                              
                 50     3.0             4-methylhexa-3,5-dienoic acid     
    penta-1,4-dien-3-ol                 ethyl 6-(2,6,6-trimethylcyclohex-1
                                        -                                 
    (vinylionol)                        enyl)-4-methylhexa-3,5-dienoate,  
    100                                 bp. 159-162° C.            
                                     25%                                  
                                        mixture: fruity, damsony          
                                        apricot                           
20  3-Ethylpent-1-en-3-ol                                                 
                 EtOH   1.0  600                                          
                                22   11%                                  
                                        4-ethylpent-3-enoic acid          
    120          60     3.0          54%                                  
                                        ethyl 4-ethylpent-3-enoate,       
                                        bp. 106-107° C./52 mbar    
                                     65%                                  
                                        ester: pungent, greenish, fruity  
21  4-Vinylheptan-4-ol                                                    
                 EtOH   1.0  600                                          
                                17    6%                                  
                                        4-n-propylhept-3-enoic acid       
    100          50     3.0          56%                                  
                                        ethyl 4-n-propylhept-3-enoate,    
                                        bp. 53-55° C./4 mbar       
                                     62%                                  
                                        ester: fruity, green, rubbery     
22  1-Vinylcyclododecan-1-ol                                              
                 EtOH   1.0  600                                          
                                23    8%                                  
                                        3-(cyclododecylidene)-propionic   
                                        acid                              
    100          50     3.0          61%                                  
                                        ethyl 3-(cyclododecylidene)-propio
                                        n-                                
                                        ate, bp. 144-146° C./4     
                                        mbar                              
                                     69%                                  
                                        ester: fatty, tart, slightly      
                                        sweetish,                         
                                        balsamic                          
23  2-Methyl-1-vinyl-cyclo-                                               
                 EtOH   1.0  600                                          
                                17    5%                                  
                                        3-(2-methylcyclohexylidene)-      
    hexan-1-ol   46.7   3.0             propionic acid                    
    93.5                             51%                                  
                                        ethyl 3-(2-methylcyclohexylidene)-
                                     56%                                  
                                        propionate, bp. 116-122°   
                                        C./28 mbar                        
24  3-Methyl-1-vinyl-cyclo-                                               
                 EtOH   1.0  600                                          
                                34    5%                                  
                                        3-(3-methylcyclohexylidene)-      
    hexan-1-ol   46     3.0             propionic acid                    
    92                               73%                                  
                                        ethyl 3-(3-methylcyclohexylidene)-
                                     78%                                  
                                        propionate, bp. 105-110°   
                                        C./16 mbar                        
                                        ester: fruity, sweetish, fatty    
                                        alcohol-like                      
25  1-Vinyl-cyclohexan-1-ol                                               
                 EtOH   2.5  300                                          
                                17   12%                                  
                                        3-(cyclohexylidene)-propionic     
                                        acid                              
    876          500    7.5          58%                                  
                                        ethyl 3-(cyclohexylidene)-propiona
                                        te                                
                                     70%                                  
                                        bp. 130° C./30 mbar        
                                        ester: fruity, strawberry-like,   
                                        tart                              
26  3,3-Dimethyl-1-vinyl-                                                 
                 EtOH   1.0  600                                          
                                 7    3%                                  
                                        3-(3,3-dimethylcyclohexylidene)-  
    cyclohexan-1-ol                                                       
                 50     3.0             propionic acid,                   
    90                               76%                                  
                                        ethyl 3-(3,3-dimethylcyclohexylide
                                        ne)-                              
                                        propionate, bp. 138-140°   
                                        C./40 mbar                        
                                     79%                                  
                                        q = 50:50                         
                                        ester: woody, fruity, greenish    
27  Mixture of 2,2,4- and                                                 
                 EtOH   1.0  600                                          
                                16    4%                                  
                                        3-(2,2,4/2,4,4-trimethylcyclopenty
                                        li-                               
    2,4,4-trimethyl-1-vinyl-                                              
                 50     3.0             dene)-propionic acid              
    cyclopentan-1-ol                 58%                                  
                                        ethyl 3-(2,2,4/2,4,4-trimethylcycl
                                        o-                                
    100                                 pentylidene)-propionate,          
                                        bp. 62-63° C./4 mbar       
                                     62%                                  
                                        ester: green, earthy, fungal,     
                                        woody                             
28  1-Vinyl-1-hydroxy-                                                    
                 EtOH   1.0  600                                          
                                13    5%                                  
                                        2,3-benzocyclohexylid-1-enepropion
                                        ic                                
    1,2,3,4-tetrahydro-                                                   
                 100    3.0             acid                              
    naphthalene                      60%                                  
                                        ethyl 2,3-benzocyclohexylid-1-ene-
    100                                 propionate, bp. 110° C./4  
                                        mbar                              
                                     65%                                  
                                        q = 70:30                         
29  9-Vinyl-9-hydroxy-                                                    
                 EtOH   1.0  600                                          
                                10   &lt;1%                                  
                                        3-(fluorenylid-9-ene)-propionic   
                                        acid                              
    fluorene     50     3.0           83%                                 
                                        ethyl 3-(fluorenylid-9-ene)-propio
                                        n-                                
    85                                83%                                 
                                        ate, bp. 60-65° C.         
30  3,3-Diphenylprop-1-en-3-                                              
                 EtOH   1.0  600                                          
                                10    8%                                  
                                        4,4-diphenylbut-3-enoic acid      
    ol           50     3.0          72%                                  
                                        ethyl 4,4-diphenylbut-3-enoate,   
    73                               80%                                  
                                        bp. 168° C./4 mbar         
31  3-Phenylbut-1-en-3-ol                                                 
                 EtOH   1.0  600                                          
                                 8    5%                                  
                                        4-phenyl-but-3-enoic acid         
    70           50     3.0          40%                                  
                                        ethyl 4-phenyl-but-3-enoate bp.   
                                        159° C./40 mbar            
                                     30%                                  
                                        2-methyl-2-phenylbutyrolactone,   
                                     75%                                  
                                        bp. 165-167° C./40 mbar    
32  3-(3,3-Dimethylcyclo-hex-                                             
                 EtOH   1.0  600                                          
                                 5    8%                                  
                                        4-(3,3-dimethylcyclohex-1-yl)-pent
                                        -                                 
    1-yl)-but-1-ene                                                       
                 50     3.0             3-enoic acid                      
    100                              65%                                  
                                        ethyl 4-(3,3-dimethylcyclohex-1-yl
                                        )-                                
                                        pent-3-enoate,                    
                                        bp. 80-82° C./4 mbar       
                                     73%                                  
                                        q = 1:1                           
33  3-Cyclopropylbut-1-en-3-                                              
                 EtOH   1.0  600                                          
                                15    4%                                  
                                        4-cyclopropylbut-3-enoic acid     
    ol           50     3.0          38%                                  
                                        ethyl 4-cyclopropylbut-3-enoate,  
    100                              42%                                  
                                        bp. 113-115° C./44 mbar    
34  3-Methoxybut-1-en-3-ol                                                
                 EtOH   1.0  530                                          
                                12    4%                                  
                                        4-methoxypent-3-enoic acid        
    80           50     3.0          38%                                  
                                        ethyl 4-methoxypent-3-enoate,     
                                        bp. 117-125° C./74 mbar    
                                     42%                                  
                                        q = 80:20                         
35  3-Methyl-4-phenyl-but-1-                                              
                 EtOH   1    680                                          
                                20   12%                                  
                                        4-methyl-5-phenyl-but-3-enoic     
                                        acid                              
    en-3-ol      50     3            68%                                  
                                        ethyl 4-methyl-5-phenyl-but-3-enoa
                                        te,                               
    101                                 bp. 98-99° C./4 mbar       
                                     80%                                  
                                        q = 65:35                         
                                        ester: green, pelargonium leaves  
36  1-Vinyl-cycloheptan-1-ol                                              
                 EtOH   1    600                                          
                                13   11%                                  
                                        3-cycloheptylidene-propionic      
                                        acid                              
    105          45     3            58%                                  
                                        ethyl 3-cycloheptylidene-propionat
                                        e                                 
                                     69%                                  
                                        bp. 132° C./24 mbar        
37  3-(4-Methoxyphenyl)-but-                                              
                 EtOH   1    300                                          
                                16    2%                                  
                                        4-(4-methoxyphenyl)-pent-3-enoic  
                                        acid                              
    1-en-3-ol    50     3            40%                                  
                                        ethyl 4-(4-methoxyphenyl)-pent-3- 
    100                                 enoate, bp. 157-159° C./40 
                                        mbar                              
                                     33%                                  
                                        5-(4-methoxyphenylmethyl)-butyrola
                                        c-                                
                                     75%                                  
                                        tone, bp. 165-167° C./40   
                                        mbar                              
38  4-tert.-Butoxy-hex-1-                                                 
                 EtOH   0.5  300                                          
                                11   11%                                  
                                        5-tert.-butoxy-hept-3-enoic acid  
    en-3-ol      50     1.5          52%                                  
                                        ethyl 5-tert.-butoxy-hept-3-enoate
                                        ,                                 
    58                               63%                                  
                                        bp. 85-86° C./4 mbar       
39  3-(2-Methoxyphenyl)-but-                                              
                 EtOH   0.5  300                                          
                                26    8%                                  
                                        4-(2-methoxyphenyl)-pent-3-enoic  
                                        acid                              
    1-en-3-ol    50     1.5          72%                                  
                                        ethyl 4-(2-methoxyphenyl)-pent-3- 
    37                               80%                                  
                                        enoate, bp. 122-128° C./4  
                                        mbar                              
40  2-Benzyl-1-vinyl-cyclo-                                               
                 EtOH   1    600                                          
                                26    4%                                  
                                        3-(2-benzylcyclohexylidene)-propio
                                        nic                               
    hexan-1-ol   37     3               acid                              
    37                               79%                                  
                                        ethyl 3-(2-benzylcyclohexylidene)-
                                     83%                                  
                                        propionate, bp. 163-182°   
                                        C./4 mbar                         
41  3-(Tetrahydropyran-3-yl)-                                             
                 EtOH   1    650                                          
                                13   11%                                  
                                        4-(tetrahydropyran-3-yl)-but-3-   
    prop-1-en-3-ol                                                        
                 50     3               enoic acid                        
    100                              66%                                  
                                        ethyl 4-(tetrahydropyran-3-yl)-but
                                        -                                 
                                        3-enoate, bp. 72-74° C./4  
                                        mbar                              
                                     77%                                  
                                        q = 90:10                         
42  Bis-(4-chlorophenyl)-                                                 
                 EtOH   1    650                                          
                                 7    8%                                  
                                        4,4-di-(4-chlorophenyl)-but-3-enoi
                                        c                                 
    vinylcarbinol                                                         
                 50     3               acid                              
    100                              63%                                  
                                        ethyl 4,4-di-(4-chlorophenyl)-but-
                                        3-                                
                                     71%                                  
                                        enoate, bp. 208-212° C./4  
                                        mbar                              
43  Bis-(4-fluorophenyl)-                                                 
                 EtOH   1    650                                          
                                 6    5%                                  
                                        4,4-di-(4-fluorophenyl)-but-3-    
    vinylcarbinol                                                         
                 30     3               enoic acid                        
    115                              68%                                  
                                        ethyl 4,4-di-(4-fluorophenyl)-but-
                                     73%                                  
                                        3-enoate, bp. 148-153°     
                                        C./4 mbar                         
44  1-Vinyl-2,3-6,7-dibenzo-                                              
                 EtOH   1    650                                          
                                 8    4%                                  
                                        3-(2,3-6,7-dibenzo-cyclohept-4-en-
                                        1-                                
    cyclohept-4-en-1-ol                                                   
                 50     3               ylidene)-propionic acid           
    105                              69%                                  
                                        ethyl 3-(2,3-6,7-dibenzo-cyclohept
                                        -                                 
                                        4-en-1-ylidene)-propionate,       
                                     73%                                  
                                        bp. 168-170° C./4 mbar     
45  1-Vinyl-2,3-6,7-dibenzo-                                              
                 EtOH   1    650                                          
                                 6    3%                                  
                                        3-(2,3-6,7-dibenzocyclohept-1-yli-
    cycloheptan-1-ol                                                      
                 50     3               dene-propionic acid               
    100                              69%                                  
                                        ethyl 3-(2,3-6,7-dibenzocyclohept-
                                        1-                                
                                     72%                                  
                                        ylidene-propionate, bp.           
                                        182-185° C./4 mbar         
46  3-(2-Methoxyphenyl)-prop-                                             
                 EtOH   1    650                                          
                                12    8%                                  
                                        4-(2-methoxyphenyl)-but-3-enoic   
                                        acid                              
    1-en-3-ol    50     3            59%                                  
                                        ethyl 4-(2-methoxyphenyl)-but-3-  
    103                              67%                                  
                                        enoate, bp. 146-153° C./7  
                                        mbar                              
47  3,7-Dimethyl-octa-1,6-                                                
                 tert.-ButOH                                              
                        2.5  300                                          
                                 9   66%                                  
                                        4,8-dimethyl-nona-3,7-dienoic     
                                        acid                              
    dien-3-ol    500    7.5          20%                                  
                                        tert.-butyl 4,8-dimethyl-nona-3,7-
    1,000                            86%                                  
                                        dienoate, bp. 97-98° C./6  
                                        mbar                              
48  3,7-Dimethyl-oct-1-en-3-                                              
                 tert.-ButOH                                              
                        2.5  300                                          
                                13   64%                                  
                                        4,8-dimethyl-non-3-enoic acid,    
    ol           500    7.5          18%                                  
                                        tert.-butyl 4,8-dimethyl-non-3-eno
                                        ate,                              
    1,000                            82%                                  
                                        bp. 88° C./4 mbar          
49  3-Methyl-but-1-en-3-ol                                                
                 tert.-ButOH                                              
                        2.5  300                                          
                                22   71%                                  
                                        4-methyl-but-3-enoic acid         
    1,000        500    7.5          13%                                  
                                        tert.-butyl 4-methyl-but-3-enoate,
                                     84%                                  
                                        bp. 87° C./48 mbar         
50  3-Methyl-but-1-en-3-ol                                                
                 tert.-ButOH                                              
                        2.5  300                                          
                                41   58%                                  
                                        4-methyl-but-3-enoic acid         
    1,000        500    7.5**        15%                                  
                                        tert.-butyl 4-methyl-but-3-enoate,
                                     73%                                  
                                        bp. 87° C./48 mbar         
51  Oct-1-en-3-ol                                                         
                 tert.-ButOH                                              
                        2.5  300                                          
                                32   63%                                  
                                        oct-3-enoic acid                  
    1,000        500    7.5          12%                                  
                                        tert.-butyl oct-3-enoate,         
                                     75%                                  
                                        bp. 72° C./6 mbar          
52  3,7,11-Trimethyl-dodeca-                                              
                 tert.-ButOH                                              
                        2.5  300                                          
                                32   74%                                  
                                        4,8,12-trimethyl-trideca-3,7,11-  
    1,6,10-trien-3-ol                                                     
                 500    7.5             trienoic acid                     
    (nerolidol)                       3%                                  
                                        tert.-butyl 4,8,12-trimethyl-tride
                                        ca-                               
    1,000                               3,7,11-trienoate                  
                                     77%                                  
                                        isomer mixture                    
53  3,7,11-Trimethyl-dodeca-                                              
                 tert.-ButOH                                              
                        2.5  300                                          
                                28   82%                                  
                                        4,8,12-trimethyl-trideca-3,7,11-  
    1,6,10-trien-3-ol                                                     
                 500    15**            trienoic acid                     
    (nerolidol)                       2%                                  
                                        tert.-butyl 4,8,12-trimethyl-tride
                                        ca-                               
    1,000                               3,7,11-trienoate                  
                                     84%                                  
                                        isomer mixture                    
54  3,7,11,15-Tetramethyl-                                                
                 tert.-ButOH                                              
                        2.5  300                                          
                                 8   72%                                  
                                        4,8,12,16-tetramethyl-heptadec-3- 
    hexadec-1-en-3-ol                                                     
                 500    7.5             enoic acid                        
    (isophytol)                       7%                                  
                                        tert.-butyl 4,8,12,16-tetramethyl-
    490                                 heptadec-3-enoate,                
                                     79%                                  
                                        isomer mixture                    
55  Oct-1-en-3-ol                                                         
                 --     2.5  280                                          
                                15   84%                                  
                                        non-3-enoic acid, bp.             
                                        93-94° C./4 mbar           
    1,210        --     7.5             q = 85:15                         
56  3,7-Dimethyl-octa-1,6-                                                
                 --     2.5  280                                          
                                16   83%                                  
                                        4,8-dimethyl-nona-3,7-dienoic     
                                        acid,                             
    dien-3-ol (linalool)                                                  
                        7.5             bp. 120-124° C./4 mbar     
    1,500                               q = 82:18                         
57  3-Methyl-but-1-en-3-ol                                                
                 --     2.5  240                                          
                                16   83%                                  
                                        4-methyl-but-3-enoic acid,        
    1,500        --     7.5  ***        bp. 70-71° C./4 mbar       
58  3,7,11-Trimethyl-dodeca-                                              
                 --     2.5  240                                          
                                22   70%                                  
                                        trimethyl-trideca-3,7,11-trienoic 
    1,6,10-trien-3-ol                                                     
                 --     7.5             acid, bp. 165-170° C./1    
                                        mbar                              
    560                                                                   
__________________________________________________________________________
 *Individual yields not determined                                        
 **nHexyldiphenylphosphine                                                
 ***Temperature 80° C.