Conditions have been established for the catalytic hydrogenation of (+)-α-pinene to give over 98% of (+)-cis-pinane. Modification of the reaction conditions leads to the formation of over 50%trans-pinane. Conditions have also been established for the hydrogenation of (+)-car-3-ene giving over 98% of (–)-cis-carane. Trans-carane has not yet been obtained, but under appropriate conditions (+)-car-3-ene affords quantitative yields of 1,1,4-trimethylcycloheptane, suggested intermediates in the formation of which have been isolated, including (+)-car-2-ene.