303015-27-2

Upstream product

• 58479-61-1 tert-butylchlorodiphenylsilane 
• 210906-84-6 (S)-1-cyano-2-hydroxy-5-trimethylsilyl-4-pentyne 
• 1066-54-2 trimethylsilylacetylene 
• 178751-54-7 (S)-2-hydroxy-5-trimethylsilyl-1-p-toluenesulfonyloxy-4-pentyne 

Downstream Products

• 303015-28-3 3-(tert-butyl-diphenyl-silanyloxy)-6-trimethylsilanyl-hex-5-ynal 
• 152032-73-0 (3S,5R)-3-[(t-butyldimethylsilyl)oxy]-5-[(t-butyldiphenylsilyl)oxy]-1-octen-7-yne 
• 303015-33-0 (3R,5R)-3-[(t-butyldimethylsilyl)oxy]-5-[(t-butyldiphenylsilyl)oxy]-1-octen-7-yne 
• 303015-29-4 (5S)-5-[(t-butyldiphenylsilyl)oxy]-3-hydroxy-8-trimethylsilyl-1-octen-7-yne 
• 303015-30-7 (3S,5S)-5-[(t-butyldiphenylsilyl)oxy]-3-hydroxy-1-octen-7-yne 
• 303015-32-9 (3R,5S)-5-[(t-butyldiphenylsilyl)oxy]-3-hydroxy-1-octen-7-yne 

Relevant 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

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.