178751-54-7Relevant academic research and scientific papers
Synthesis and biological evaluations of A-ring isomers of 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3
Ikeda, Masahiko,Takahashi, Kazuhiko,Dan, Akihito,Koyama, Kohji,Kubota, Katsumi,Tanaka, Tomoyuki,Hayashi, Masaji
, p. 2157 - 2166 (2000)
The activated vitamin D3 derivative 26,27-F6-1α,25(OH)2D3 (2a), its three A-ring diastereomers (2b, 2c, 2d), and 5,6-trans isomer (2e) were prepared. Two analogues (2b, 2c) of these isomers were synthesized by a palladium catalyzed coupling reaction using vinyl bromide 5 and enynes (6a, 6b), which were derived from readily commercially available 2S-(+)-glycidyl p-toluenesulfonate 7, as a common starting material. Competitive vitamin D receptor (VDR) binding affinities of these diastereomers of 2a were evaluated. Interestingly, the stereochemical effects at C-1,3 of 2a were considerably more moderate than those of 1α,25(OH)2D3 (1). In particular, isomerization at the 5,6-double bond of 2a only slightly reduced VDR affinity, whereas 5,6-trans-1α,25(OH)2D3 had a significantly lower binding affinity than 1. Copyright (C) 2000 Elsevier Science Ltd.
Versatile Synthesis of Enantiomerically Pure 2-Alkoxy-1-ethynylcyclopropanes and Their Application in the Synthesis of Enantiomerically Pure Bicyclo-oct-1-en-3-ones
Braese, Stefan,Schoemenauer, Sten,McGaffin, Gregory,Stolle, Andreas,Meijere, Armin de
, p. 545 - 555 (2007/10/03)
A variety of chiral, nonracemic 2-alkoxy-1-alkynylcylopropanes 7 were synthesized in good to very good yields from enantiomerically pure glycidol derivatives (glycidol tosylate, epichlorohydrin) by boron trifluoride promoted addition of lithium trimethyls
