(10Z)- and (10E)-19-Fluoro-1.ALPHA.,25-dihydroxyvitamin D3. An Improved Synthesis via 19-Nor-10-oxo-vitamin D.
作者:Masato SHIMIZU、Akiko OHNO、Sachiko YAMADA
DOI:10.1248/cpb.49.312
日期:——
group of (5E)-19-nor-10-oxo-vitamin D to the E and Z fluoromethylene group was achieved through a two-step sequence involving a reaction of lithiofluoromethyl phenyl sulfone followed by the reductive desulfonylation of the alpha-fluoro-beta-hydroxy sulfone. The dye-sensitized photoisomerization of the (5E)-19-fluorovitamin D afforded the desired (5Z)-19-fluorovitamin D derivatives, (10Z)- and (10E)-19-fluoro-1alpha
Synthesis and biological evaluation of all eight possible A-ring diastereomers of 2-methyl-20-epi-1,25-dihydroxyvitamin D-3 are described. Among the analogues synthesized, 2 alpha-methyl-20-epi-1 alpha,25-dihydroxyvitamin D-3 exhibited exceptionally high potency. The double modification of 2-methyl substitution and 20-epimerization yielded analogues with unique activity profiles. (C) 1998 Elsevier Science Ltd. All rights reserved.