Synthesis of 9-Alkylated Calcitriol and Two 1α,25-Dihydroxy-9-methylene-10,19-dihydrovitamin D<sub>3</sub> Analogues with a Non-natural Triene System by Thermal Sigmatropic Rearrangements
作者:Urszula Kulesza、Rita Sigüeiro、Antonio Mouriño、Rafal R. Sicinski
DOI:10.1021/jo302513e
日期:2013.2.15
1α,25-(OH)2-9α-Methylvitamin D3 (4), the first known analogue of the natural hormone 1α,25-(OH)2D3 (3) with an alkyl substituent at C-9, and two 1α,25-(OH)2-9-methylene-10,19-dihydrovitamin D3 analogues (7 and 8) with an unprecedented non-natural triene system were synthesized by thermal isomerization of 1α,25-(OH)2-9-methylprevitamin D3 (6). Three alternative approaches (Sonogashira, Stille, or stereoselective
1α,25-(OH)2 -9α-Methylvitamin d 3(4),天然激素1α,25-(OH)的第一个已知的类似物2 d 3(3与C-9的烷基取代基),以及两个1α,25-(OH)2 -9 -亚甲基- 10,19-二dihydrovitamin d 3个类似物(7和8)以前所未有的非天然三烯体系由1α的热异构化合成,25-(OH)2 -9 -甲基维生素原D 3(6)。三种替代方法(Sonogashira,Stille或叔炔丙醇的立体选择性脱水)已成功用于构建维生素原6的二烯炔前体,该前体维生素6具有两个能够参与[1,7]-σ氢转移的甲基。