tert-Butyl-dimethyl-((1R,4aR,4bS,8aS,10aR)-4b,8,8,10a-tetramethyl-2-methylene-tetradecahydro-phenanthren-1-ylmethoxy)-silane

(1R,4aS,4bR,8aR,10aS)-3,4,4a,4b,5,6,7,8,8a,9,10,10a-dodecahydro-1-methoxycarbonyl-4b,8,8,10a-tetramethyl-trans-anti-trans-phenanthrene-2(1H)-one-2-[((1S,2S)-di(hydroxymethyl))ethylene acetal]