(((1R,3R)-5-(2-((1S,3aR,7aR,E)-1-(5-methyl-5-((triethylsilyl)oxy)hexyl)octahydro-4H-inden-4-ylidene)ethylidene)-2-methylenecyclohexane-1,3-diyl)bis(oxy))bis(tert-butyldimethylsilane) 在
D(+)-10-樟脑磺酸 作用下,
以
正丁醇 为溶剂,
以77%的产率得到1α,25-dihydroxy-2-methylene-18,19,21-trinorvitamin D3