(S)-2-[(1R,3aR,4S,7aR)-octahydro-4-[(1,1-dimethylethyl)dimethylsilyloxy]-7a-methyl-1H-inden-1-yl]propanal

1α-((tert-butyldimethylsilyl)-oxy)-6,7-didehydro-24-(methoxycarbonyl)-25,26,27-trisnorprevitamin D3 tert-butyldimethylsilyl ether