25-dihydroxyvitamin D3 (6: KH-1060) were convergently synthesized. Preparation of the CD-ring portions with modified side chains of 5 and 6, followed by palladium-catalyzed cross-coupling with the A-ring enyne synthons (20a-d), (3S,4S,5R)-, (3S,4R,5R)-, (3S,4S,5S)- and (3R,4R,5S)-3,5-bis[(tert-butyldimethylsilyl)oxy]-4-methyloct-1-en-7-yne, afforded two sets of four A-ring stereoisomers of 20-epi-2,22-dimethyl-1
20-epi-22R-
甲基-1α,25-二羟基
维生素D3(5)和20-epi-24,26,27-trihomo-22-oxa-1alpha,25-二羟基
维生素D3的八个
2-甲基取代的类似物(6: KH-1060)聚合合成。制备具有5和6修饰侧链的
CD环部分,然后与A环
烯炔合子(20a-d),(3S,4S,5R)-,(3S,4R)进行
钯催化的交叉偶联,5R)-,(3S,4S,5S)-和(3R,4R,5S)-3,5-双[(叔丁基二
甲基甲
硅烷基)
氧基] -4-
甲基辛-1-
烯-7-炔基组的四个20-epi-
2,22-二
甲基-1,25-二羟基
维生素D3(7a-d)和20-epi-24,26,27-trihomo-2-methyl-22-oxa-的A环立体异构体1,25-二羟基
维生素D3(8a-d)。根据与
天然激素相比对
维生素D受体(VDR)的亲和力和HL-60细胞分化诱导活性的活性,评估了杂交类似物的
生物学特性。