Process for the selective hydrogenation of compounds comprising endo and exocyclic unsaturations

A process for the selective hydrogenation in the presence of a catalyst of a polyunsaturated cyclic compound comprising at least one endocyclic carbon-carbon double bond and at least one terminal exocyclic carbon-carbon double bond, said double bonds not being conjugated, to form a mixture essentially containing a compound whose ring is saturated and which comprises at least one terminal exocyclic double bond, in which process the polyunsaturated cyclic compound is brought into contact in the presence of hydrogen at from 1 to 10 MPa and at a temperature of from 0.degree. to 100.degree. C. with a catalyst including a support and

• a) from 0.1 to 5% by weight of at least one metal from Group VIII selected from the group consisting of iridium, osmium, nickel, palladium, platinum and rhodium, and
• b) from 0.01 to 15% by weight of at least one metal from Group IVa selected form the group consisting of tin, germanium and lead, the molar ratio between said metal or metals of Group VIII and that or those of Group IVa being between 0.3 and 3 wherein selective hydrogenation of endocyclic carbon-carbon double bonds over exocyclic carbon-carbon double bonds in the polyunsaturated compounds is greater than 85%.