High-density liquid fuel

Claim 1

A high-density liquid fuel consisting essentially of a compound of the formula ##STR17## wherein each of m and n is 0 or 1, and each of R 1 , R 2 and R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, the sum of carbon atoms in R 1 , R 2 and R 3 being an integer of 1 to 3; prepared by reacting an aliphatic unsaturated hydrocarbon having 3 to 5 carbon atoms of the formula ##STR18## wherein R 1 , R 2 and R 3 are as defined above, with cyclopentadiene, methylcyclopentadiene and mixtures thereof in accordance with the Diels-Alder reaction to synthesize a 1:2 adduct of the unsaturated hydrocarbon and the pentadiene, and then hydrogenating the thus synthesized adduct, or by reacting 5-ethylidenenorbornene-2 with cyclopentadiene, methylcyclopentadiene or mixtures thereof in accordance with the Diels-Alder reaction to produce a 1:1 of adduct of 5-ethylidenenorbornene-2 and the pentadiene, and hydrogenating carbon-carbon double bonds in the adduct.