Epoxidation of (22E)-3β-acetoxylanosta-8, 22-dien-24-one (1) afforded the 22, 23-epoxides (2) which were led to (22R)-22-hydroxylanosterol (7a) predominantly and (22S)-22-hydroxylanosterol (8a) as a minor product in a few steps. The epimeric relationship of 7a and 8a was confirmed by Jones oxidation of 7a t) give the 3, 22-diketo compound (9), which furnished mainly (22S)-22-hydroxylanosterol (8a) on hydride reduction.
