【摘要】 首次利用薯蓣皂甙元的完整骨架经16步反应以7.6%的总收率合成了骨化三醇(1α,25-二羟基维生素D3)的光化反应前体.3-苄基保护的薯蓣皂甙元经还原开E/F环产生3,16,26-胆甾三醇-3-苄醚(5).除去化合物5C-16羟基后,其C-26羟基经消除和羟基化反应转移到C-25位.目标分子A/B环结构单元通过薯蓣皂甙元A/B环的官能团转化被构筑.按照已知的光化反应,(1S,3R)-胆甾-5,7-二烯-1,3,25-三醇能被转化成为1α,25-二羟基维生素D3.更多还原

【Abstract】 (1S,3R)-Cholesta-5,7-diene-1,3,25-triol,a photochemical reaction precursor for the preparation of 1α,25-dihydroxyvitamin D3,was synthesized by utilizing the intact skeleton of diosgenin in 16 steps in 7.6% overall yield.The reductive E/F ring opening of 3-benzyloxy-diosgenin produced 3,16,26-cholesteratriol ben-zyl ether 5.The C-26 hydroxy group was shifted to C-25 through the elimination and hydroxylation after the selective removal of C-16 hydroxyl group in 5.The A/B structural unit of the target molecule was constructed by the functional transformation of the A/B ring of diosgenin.(1S,3R)-Cholesta-5,7-diene-1,3,25-triol can be converted into 1α,25-dihydroxyvitamin D3 according to the known photochemical reaction.更多还原