Efficient synthesis and biological evaluation of all a-ring diastereomers of 1α,25-dihydroxyvitamin D3 and its 20-epimer
作者:Toshie Fujishima、Katsuhiro Konno、Kimie Nakagawa、Mayuko Kurobe、Toshio Okano、Hiroaki Takayama
DOI:10.1016/s0968-0896(99)00262-x
日期:2000.1
An improved synthesis of the diastereomers of 1alpha,25-dihydroxyvitamin D3 (1) was accomplished utilizing our practical route to the A-ring synthon. We applied this procedure to synthesize for the first time all possible A-ring diastereomers of 20-epi-1alpha,25-dihydroxyvitamin D3 (2). Ten-step conversion of 1-(4-methoxyphenoxy)but-3-ene (6), including enantiomeric introduction of the C-3 hydroxyl
利用我们通往A环合成子的实用途径,完成了1α,25-二羟基维生素D3(1)非对映异构体的合成。我们应用此程序首次合成了20-epi-1alpha,25-dihydroxyvitamin D3(2)的所有可能的A环非对映异构体。1-(4-甲氧基苯氧基)丁-3-烯(6)的十步转化,包括通过Sharpless不对称二羟基化将C-3羟基对映体引入烯烃,提供了A环烯炔的所有四种可能的立体异构体(3)。即(3R,5R)-,(3R,5S)-,(3S,5R)-和(3S,5S)-双[(叔丁基二甲基甲硅烷基)氧基] oct-1-en-7-yne总产量。钯催化的A环合成子与20-epi CD环部分的交叉偶联(5),(E)-(20S)-de-A,B-8-(溴亚甲基)胆甾醇25-ol,然后解除保护,提供了必需的20-epi-1alpha,25-二羟基维生素D3非对映异构体(2)。根据对维生素D受体(VDR)和维生素