作者:Satish C. Choudhry、Peter S. Belica、David L. Coffen、Antonino Focella、Hubert Maehr、Percy S. Manchand、Lucia Serico、Roxana T. Yang
DOI:10.1021/jo00058a034
日期:1993.3
The synthesis of 1alpha,25,28-trihydroxyvitamin-D2 (1) from vitamin-D2 is described. Approaches to the upper side-chain synthon via the chiral sulfone 15, prepared either through the enzymatic resolution of 10 or the opening of the optically pure epoxide 17 with the dianion of methyl phenyl sulfone, are described. A Julia coupling of the sulfone 15 with C-1 hydroxylated aldehyde 7, obtained from vitamin-D2, gave the (22E)-isomer 24a, which was deprotected and photoisomerized to give 1.