[(1S,2aS,2bS,6S,8aR,8bS,10aS)-6-hydroxy-8a,10a-dimethyl-1,2,2a,2b,3,5,6,7,8,8a,8b,9,10,10a-tetradecahydrocyclobuta[a]phenanthren-1-yl](2-methyl-1,3-dioxolan-2-yl)methanone