6-{(S)-1-[(3S,8S,9S,10R,13S,14S,17R)-10,13-Dimethyl-3-(tetrahydro-pyran-2-yloxy)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl]-ethyl}-4-isopropyl-5,6-dihydro-pyran-2-one 生成
trans-24-Carboxymethylen-Δ22-cholesterin