Deuterium and tritium labeling of (3-xenyl)cyclohexane by Clemmensen and Wolff-Kishner reduction.

Tritium-labeling of (3-xenyl)cyclohexane was investigated by deuterium-labeling on Clemmensen and Wolff-Kishner reduction of 2-(3-xenyl)cyclohexane. Deuterium-labeling by the Clemmensen reduction was proved to be accompanied by isotope exchange via acid-catalyzed enolyzation of the carbonyl group. Thus, the labeled (3-xenyl)cyclohexane was a mixture of compounds with various numbers of deuterium atoms. Labeling by the modified Wolff-Kishner reduction gave a mixture of compounds labeled predominantly at position 2.