@ The 26,26,26-trifluoro-1α,25-dihydroxycholecalciferol particularly the 26,26,26-trifluoro-1α,25R-dihydroxycholecalciferol essentially free of the 25S-epimer, and the 26,26,26-trifiuoro-1α,25S-dihydroxycholecalciferol essentially free of the 25R-epimer, is prepared by reacting a compound of the formula
wherein Y is trialkylated Si, with the carbanion of [3S-(3α,5β,Z)]-2-[2-methylene-3,5-bis[(1,1 - dimethylethyl)dimethylsilyloxy]cyclohexylidene)-ethyldiphenyl phosphine oxide and removing the silyl protecting groups. It exhibits enhanced vitamin D3-like activity.
26,26,26-三
氟-1α,25-二羟基胆
钙化醇,特别是 26,26,26-三
氟-1α,25R-二羟基胆
钙化醇基本上不含 25S 表聚物,以及 26,26,26-三
氟-1α,25S-二羟基胆
钙化醇基本上不含 25R 表聚物,是通过反应式如下的化合物制备的
其中 Y 为三烷基化的 Si,与 [3S-(3α,5β,Z)]-2-[2-亚甲基-3,5-双[(
1,1-二甲基乙基)二甲基
硅氧基]环己亚基)-
乙基二苯基氧化膦的碳离子反应,并除去
硅基保护基团。它具有更强的
维生素 D3 类活性。