the compounds ( 1 ) and ( 2 ) according to the present invention are prepared in accordance with , for example , the following reaction scheme : ## str7 ## wherein x has the same meaning as defined above . more specifically , norbornadiene ( 3 ) is dimerized in the presence of a combined catalyst of a ruthenium complex and an n , n - dialkyl ( meth ) acrylamide , thereby resulting in the formulation of the hydrocarbon compound ( 1 ) according to the present invention . besides , the halogenated hydrocarbon compound ( 2 ) is prepared by halogenating the hydrocarbon compound ( 1 ). norbornadiene ( 3 ) used as a raw material for the hydrocarbon compound represented by the formula ( 1 ) in the present invention is prepared with ease , for example , by the diels - alder reaction using , as raw materials , acetylene obtained by cracking of naphtha , and cyclopentadiene obtained similarly . examples of the ruthenium complex as one component of the catalyst used for the dimerization of norbornadiene ( 3 ) in the present invention include ruthenium - unsaturated hydrocarbon complexes , ruthenium carbonyl compounds , ruthenium - phosphine complexes , ruthenium - carbonyl phosphine complexes and the like . specific preferable examples thereof include ( 1 , 5 - cyclooctadiene )( 1 , 3 , 5 - cyclooctatriene ) ruthenium and dihydridocarbonyl tris ( triphenylphosphine ) ruthenium . the amount of the ruthenium complex to be used is preferably 0 . 025 - 25 mols , in particular , 0 . 5 - 5 mols , per 100 mols of norbornadiene as the raw material . as examples of the n , n - dialkyl ( meth ) acrylamide , there may be preferably used those whose alkyl moieties have 1 - 8 carbon atoms , in particular , 1 - 3 carbon atoms . of these , those containing a methyl group , ethyl group , propyl group or isopropyl group are particularly preferred . the amounts of such n , n - dialkyl ( meth ) acrylamides to be used are preferably 1 - 100 mols , in particular , 5 - 50 mols , per mol of the ruthenium complex . in order to prevent the dimerization of the n , n - dialkyl ( meth ) acrylamide , a tertiary amine may be added as a stabilizer for the catalyst in the present invention . examples of the tertiary amine include n - alkylpiperidines whose alkyl moiety has 1 - 8 carbon atoms and trialkylamines . since the tertiary amine serves not only as the stabilizer for the catalyst , but also as a solvent , no particular limitation is imposed on its amount to be used . in the compound ( 2 ) according to the present invention , the halogen atoms as the substituents include a bromine atom , fluorine atom , chlorine atom and iodine atom . the dimerization of norbornadiene ( 3 ) is conducted by adding the tertiary amine to the catalyst as needed , and reacting norbornadiene in the presence of this catalyst . in this case , the reaction may be desirably performed in an atmosphere of an inert gas such as argon gas or nitrogen gas . upon the reaction , a solvent may or may not be used . if used , no particular limitation is imposed on the kind of the solvent . the reaction may be conducted at a temperature of 10 °- 200 ° c ., preferably 50 +- 150 ° c . for 0 . 5 - 20 hours , preferably 2 - 12 hours . the thus - obtained hydrocarbon compound ( pentacyclo [ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ] tetradeca - 4 , 8 - diene ) represented by the formula ( 1 ) has a compact structure in which five 5 - membered rings are condensed , and is high in density per unit volume . therefore , this compound is effectively used as a jet - propulsion fuel for rocket and jet engines either as it is or in the form of a hydrogenated product . since the compound has two independent double bonds , it is useful as a monomer for various polymerization reactions such as radical polymerization , cationic polymerization and anionic polymerization and may also be used in rim ( reaction injection molding ) according to a metathesis reaction like cyclopentadiene ( cpd ). further , its copolymer with ethylene may be used as a material for optical lenses . furthermore , the reactivity of the double bonds contained therein can be put to good use to obtain various derivatives by halogenation , epoxidation or the like . therefore , the hydrocarbon compound is also useful as an intermediate for preparation of the various derivatives . the preparation of the halogenated hydrocarbon compound of the formula ( 2 ) from the hydrocarbon compound of the formula ( 1 ) can be performed with ease by subjecting the hydrocarbon compound of the formula ( 1 ) to halogenation in accordance with a method known per se in the art . more specifically , the hydrocarbon compound of the formula ( 1 ) is dissolved in a solvent such as chloroform to give a concentration of preferably 0 . 01 - 5 . 0 mol / liter . a gas of a halogen such as bromine is blown into this solution . alternatively , a solution of the halogen in a solvent such as chloroform is added dropwise to the above solution , whereby the halogenated hydrocarbon compound of the formula ( 2 ), in which two molecules of the halogen have been added to the double bonds in the hydrocarbon compound of the formula ( 1 ), can be obtained . in this case , the solvent is not limited to chloroform , but any solvent may be used so far as it can dissolve the hydrocarbon compound of the formula ( 1 ) and the halogen . the reaction may be conducted at a temperature of - 20 ° to 100 ° c ., preferably 30 ° to 80 ° c . the thus - obtained halogenated hydrocarbon compound ( pentacyclo [ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ]- 4 , 5 , 8 , 9 - tetrahalogenotetradecane ) represented by the formula ( 2 ) is useful as a raw material for perfume bases , and the like when the halogen atoms thereof are substituted by hydroxyl groups . the present invention will hereinafter be described in detail by reference to the following examples . however , it should be borne in mind that this invention is not limited to these examples . a 20 - ml sealed glass tube containing a magnetic stir bar therein was charged with 0 . 46 g ( 5 . 0 mmol ) of norbornadiene , and 0 . 03 1 g ( 0 . 1 mmol ) of ( 1 , 5 - cyclooctadiene ) ( 1 , 3 , 5 - cyclooctatriene ) ruthenium and 0 . 10 ml ( 1 . 0 mmol ) of n , n - dimethylacrylamide as a catalyst , and 0 . 30 ml ( 2 . 5 mmol ) of n - methylpiperidine as a stabilizer for the catalyst in an argon gas atmosphere , and then subjected to a reaction at 80 ° c . for 10 hours . the resulting reaction product was treated twice by distillation under reduced pressure ( by means of a kugelrohr - type distillation apparatus ), thereby obtaining 0 . 390 g ( yield : 85 % ) of colorless crystals . this compound had a melting point of 102 °- 104 ° c ., and was found to be pentacyclo -[ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ] tetradeca - 4 , 8 - diene represented by the formula ( 1 ) from the following analyses . elementary analysis ( wt . %): found : c , 90 . 54 ; h , 8 . 73 calculated : c , 91 . 26 ; h , 8 . 74 . ir spectrum ( kbr , cm - 1 ): 3043 , 2934 , 2902 , 1451 , 1349 , 848 , 723 . a reaction was conducted in the same manner as in example 1 except that 0 . 23 g ( 2 . 5 mmol ) of norbornadiene and 0 . 25 ml ( 2 . 5 mmol ) of n , n - dimethylacrylamide were used , thereby obtaining 0 . 219 g ( yield : 95 %) of a compound similar to the compound of example 1 . the thus - obtained compound was analyzed in the same manner as in example 1 and was found to be pentacyclo [ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ] tetradeca - 4 , 8 - diene . a reaction was conducted in the same manner as in example 1 except that 0 . 23 g ( 2 . 5 mmol ) of norbornadiene and 0 . 025 ml ( 0 . 25 mmol ) of n , n - dimethylacrylamide were used and the reaction was conducted for 8 hours , thereby obtaining 0 . 069 g ( yield : 30 %) of a compound similar to the compound of example 1 . the thus - obtained compound was analyzed in the same manner as in example 1 and was found to be pentacyclo [ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ] tetradeca - 4 , 8 - diene . a reaction was conducted under the same reaction conditions as in example 1 except that acetylene and cyclopentadiene , which are both raw materials for norbornadiene , were used instead of norbornadiene to try a direct reaction of acetylene and cyclopentadiene . it was however impossible to obtain pentacyclo [ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ]- tetradeca - 4 , 8 - diene . a solution ( concentration : 1 mol / liter ) of bromine in chloroform was added dropwise to a solution of 0 . 18 g ( 1 . 00 mmol ) of pentacyclo -[ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ]- tetradeca - 4 , 8 - diene obtained in example 1 in 1 ml of chloroform while stirring the solution of this compound , and the drop addition was stopped at the time the brown color of the chloroform solution of bromine became free from vanishing . the stirring was continued further for 30 minutes to deposit white crystals . the white crystals were collected by filtration , washed with cold chloroform and dried , thereby obtaining colorless crystals . this compound had a melting point of 232 °- 234 ° c ., and was found to be pentacyclo -[ 5 . 4 . 2 1 . 7 . 1 3 . 6 . 0 10 . 13 . 0 12 . 14 ]- 4 , 5 , 8 , 9 - tetrabromotetradecane represented by the following formula ( 4 ) from the following analyses . ## str8 ## elementary analysis ( wt . % ): found : c , 33 . 14 ; h , 3 . 06 ; br , 63 . 21 calculated : c , 33 . 37 ; h , 3 . 20 ; br , 63 . 43 . ir spectrum ( kbr , cm - 1 ): 2963 , 2939 , 1456 , 1312 , 1285 , 1229 , 1202 , 1183 , 1165 , 762 , 743 , 708 .