the products which can be used according to the invention , are the monoozonides of mono - or polyunsaturated cycloolefines having preferably from 6 to 12 carbon atoms , e . g . the monoozonides of cyclohexene , cyclooctene , cyclooctadiene , cyclodecene , cyclodecadiene , cyclododecene and cyclododecatriene , obtained , e . g ., according to one of the patents of the applicant : u . s . pat . no . 3 . 856 . 833 and italian no . 998 . 227 , and preferably dissolved in at least one polar solvent , such as e . g ., a saturated aliphatic carboxylic acid containing from 2 to 14 carbon atoms of the type of acetic , propionic and pelargonic acid . before subjecting the ozonide solution to the reaction which forms an object of the present invention and which will be called hereinafter , for simplicity &# 39 ; s sake , &# 34 ; dismutation &# 34 ;, it is convenient to carry out an extraction of the ozonide solution in the polar solvent with a liquid hydrocarbon , e . g ., cyclohexane , to remove all amounts of unreacted cycloolefine which may be present and may still be dissolved in the solutions of the ozonide in the polar solvent . generally the ozonide is dissolved in the polar solvent in concentration from 20 to 50 %, if the solution is too much diluted , it is convenient to concentrate it under a vacuum before the treatment with water and then with the alkali solution . the hydroxides of alkali and alkaline earth metal metals or the carbonates of the alkali metals may be used as alkalies . the preferred conditions are : ozonide concentration in the solvent 25 - 50 % by weight , temperature from 5 ° to 25 ° c ., room pressure , ph from 8 to 12 , use of sodium hydroxide as alkaline base . it is possible to operate not only with the polar solvent alone but also in the presence of a hydrocarbon solvent , e . g ., cyclohexane , which promotes the separation as it tends to dissolve the dialdehyde as it is formed , while the dicarboxylic acid remains dissolved in the aqueous phase in the form of the salt of the alkali or earth - alkali metal which has been added . the control of the ph of the solution is conveniently effected with an electronic instrument for measuring the ph chosen among those normally used in chemical operations . the solution of monoozonide ( obtained , e . g ., according to one of the examples of the u . s . pat . no . 3 . 856 . 833 or italian no . 998 . 227 ) is extracted with hydrocarbon solvent , e . g . cyclohexane , is concentrated under a vacuum to a concentration close to 50 %, and is suspended in water , the water is separated by decantation . thereafter the ph measuring electrode is immersed in the reaction vessel and is connected to a suitable indicator instrument , the temperature is brought from 10 ° c . to 18 ° c . by external cooling of the reaction vessel and the alkali hydroxide ( or carbonate ) aqueous solution is added at such a rate as to maintain the ph at the predetermined value , which is anyway lower than 12 . generally , after the initial phase , the ph value increases at each addition of the alkaline solution and thereafter decreases with time and finally becomes stabilized . the reaction is considered to be ended when the ph value does not decrease at a further addition . it is also possible to follow the progress of the ozonide conversion by the titration of the active or peroxidic oxygen , by analysis with a potassium iodide solution , according to the classic peroxide analysis method . at the end of the reaction the dialdehyde is decanted from the underlying liquid or even extracted , e . g ., with ether , benzene or cyclohexene . the carboxyxlic acid is suitably recovered from the aqueous solution in which it is in the form of salt , by acidifying it , e . g ., with sulphuric acid . a further object of the present invention is the saturated or unsaturated α , ω - dialdehyde and the saturated or unsaturated α , ω - diacid obtained by the process of the present invention . preparation of the dodeca - 4 , 8 - diene - 1 , 12 - dioic acid and of the dodeca - 4 , 8 - diene - 1 , 12 - dialdehyde by &# 34 ; dismutation &# 34 ; of the monoozonide of cyclododecatriene 1100 parts of a solution of the monozonide of cyclododecatriene in acetic acid , obtained in a manner analogous to what is described in example 1 of italian pat . no . 998 . 227 , however in the absence of acetic anhydride , having an active oxygen titre of 3 . 75 meq / g ( corresponding to a total of 4125 meq , viz . ## equ1 ## parts of ozonide ) are extracted with cyclohexane ( 5 extractions with 300 parts of cyclohexane each time ). after the extraction 1020 parts of acetic solution of ozonide remain , having the titre 3 . 975 meq / g ( corresponding to a total of 4054 . 5 meq , viz . to 425 . 7 parts of ozonide ). 500 parts of said ozonide acetic solution , containing 208 . 6 parts of ozonide , is poured under stirring into a vessel provided with a bottom cock and a cooling jacket , containing 1050 parts of water . an oily top layer and a bottom aqueous layer are obtained . the bottom layer is drawn off . 200 parts of water are added again 4 times , and the decanted water is drawn off each time ( total h 2 o 1850 parts ). 2 . 95 parts of ozonide are found by iodometric analysis in said water , so that the remaining ozonide is 205 . 65 parts . 250 parts of water are added to the remaining oil and a thermometer and an electrode for measuring the ph are introduced into the vessel , while cooling the jacket of the vessel by circulation of water at 16 ° c . a 9 . 944 % naoh aqueous solution is charged into a dripping funnel placed on the lid of the vessel and the dripping is begun under stirring . the following data have been found : ______________________________________ temperature naoh addedtime ( minutes ) ° c . ph ( parts by volume ) ______________________________________ 0 16 2 0 5 18 10 . 5 1620 19 10 . 5 10035 20 9 . 5 20040 20 8 . 0 20055 19 10 . 5 30080 19 10 . 8 40090 21 10 . 5 500102 21 10 . 8 600117 20 10 . 5 700135 20 10 . 7 750145 20 11 . 0 755______________________________________ the addition of the naoh solution is then discontinued and the product is allowed to rest overnight . two phases are present in the vessel , an upper oily phase and a lower aqueous phase . peroxidic oxygen is present in traces in the oily layer , while it is absent in the aqueous layer . the naoh solution added has been found to be 880 parts at 9 . 944 % concentration , corresponding to 87 . 5 parts of an anhydrous naoh , corresponding to 2 . 19 parts by moles . the ozonide charged in 205 . 65 parts , viz . 0 . 98 parts by moles . the reaction product is extracted with ether , the ether solution is dried over sodium sulphate , it is evapotated to dryness and a residue is obtained of 113 . 8 parts of raw dodeca - 4 , 8 - diene - 1 , 12 - dialdehyde having the following analytic titres ______________________________________ calculated for the dodeca - 4 , 8 - found for the diene - 1 , 12 - dodeca - 4 , 8 - diene - dialdehyde 1 , 12 - dialdehyde______________________________________aldehyde groups ( meq / g ) 10 . 3 9 . 5 ( with h . sub . 2 noh -- hcl ) double bonds ( in moles 10 . 3 9 . 8h . sub . 2 / g ) ( by hydrogenation ) ______________________________________ the product obtained is a straw colored oil which has a boiling point of 101 °- 103 ° c . at 0 . 07 mmhg , which is purified by distillation . the aqueous phase which remains after extraction with ether is acidified with diluted h 2 so 4 to ph 1 and is extracted once more with ether . the ether is washed with water , is dried over sodium sulphate and evaporated to dryness . a residue ( 101 . 6 parts ) is obtained which melts at 58 °- 60 ° c . and is constituted by raw dodeca - 4 , 8 - diene - 1 , 12 - dioic acid , as shown by the following analytical data . ______________________________________ found for calculated for dodeca - 4 , 8 - dodeca - 4 , 8 - diene - diene - 1 , 12 - 1 , 12 - dioic acid dioic acid______________________________________acidity meq / g 8 . 85 8 . 6double bonds ( moles h . sub . 2 / g ) 8 . 85 8 . 5______________________________________