[G-3H] ergosterol; location of tritium in rings A and B

Abstract

[G-³H] Ergosterol was prepared from ergosterone by catalytic tritium exchange in aqueous dimethylformamide on a platinum catalyst, followed by enol acetylation and reduction with sodium borohydride. The tritium was found to be distributed 41% at the 1α-, 1β-, 2-, and 4-positions, 29% at the 6- and 7-positions, and 30% in the remaining part of the molecule.