502495-26-3

Basic information

• Product Name: Silane, [[(1R,3S,5Z)-5-(bromomethylene)-4-methylene-1,3-cyclohexanediyl]bis( oxy)]bis[(1,1-dimethylethyl)dimethyl-
• CAS NO: 502495-26-3
• Molecular Formula: C20H39BrO2Si2
• Molecular Weight: 447.603
• Mol File: 502495-26-3.mol
• Article Data: 2

Chemical Properties

• CAS DataBase Reference: Silane, [[(1R,3S,5Z)-5-(bromomethylene)-4-methylene-1,3-cyclohexanediyl]bis( oxy)]bis[(1,1-dimethylethyl)dimethyl-(CAS DataBase Reference)
• NIST Chemistry Reference: Silane, [[(1R,3S,5Z)-5-(bromomethylene)-4-methylene-1,3-cyclohexanediyl]bis( oxy)]bis[(1,1-dimethylethyl)dimethyl-(502495-26-3)
• EPA Substance Registry System: Silane, [[(1R,3S,5Z)-5-(bromomethylene)-4-methylene-1,3-cyclohexanediyl]bis( oxy)]bis[(1,1-dimethylethyl)dimethyl-(502495-26-3)

Safety Data

• Hazardous Substances Data: 502495-26-3(Hazardous Substances Data)

Upstream product

• 502495-29-6 (Z)-(1S,2S,5R)-2-bromomethyl-3-[bromo(trimethylsilyl)methylene]-5-(tert-butyldimethylsilyloxy)cyclohexanol 
• 502495-28-5 acetic acid (S)-5-hydroxy-8-(trimethylsilyl)octa-2,7-diynyl ester 
• 502495-27-4 (S)-8-(trimethylsilyl)octa-2,7-diyne-1,5-diol 
• 161167-56-2 {(2S,3S)-3-[(R)-2-(tert-Butyl-dimethyl-silanyloxy)-5-trimethylsilanyl-pent-4-ynyl]-oxiranyl}-methanol 
• 161055-36-3 (2S,3R)-2-[(R)-2-(tert-Butyl-dimethyl-silanyloxy)-5-trimethylsilanyl-pent-4-ynyl]-3-iodomethyl-oxirane 
• 161055-39-6 (3S,5R)-5-(tert-butyldimethylsilyloxy)-8-(trimethylsilyl)oct-1-en-7-yn-3-ol 
• 161055-33-0 (S,E)-5-(tert-butyldimethylsilyloxy)-8-(trimethylsilyl)oct-2-en-7-yn-1-ol 
• 143724-89-4 Trimethyl-((R)-3-oxiranyl-prop-1-ynyl)-silane 
• 502495-30-9 (Z)-(2S,3S,5R)-2-bromomethyl-1-[bromo(trimethylsilyl)methylene]-3,5-bis(tert-butyldimethylsilyloxy)cyclohexane 

Downstream Products

• 32222-06-3 calcitriol 
• 599165-21-6 3β-tert-butyldimethylsilyl-1α-tert-butyldimethylsilyloxy-25-trimethylsilyloxy-19-norvitamin D₃ 
• 1027425-65-5 (1S,5R)-1,5-Bis-(tert-butyl-dimethyl-silanyloxy)-3-[(E)-(R)-7,11-dimethyl-11-triethylsilanyloxy-dodec-2-en-(Z)-ylidene]-2-methylene-cyclohexane 

Relevant articles and documents

New Convergent Synthesis of 1α,25-Dihydroxyvitamin D3 and Its Analogues by Suzuki-Miyaura Coupling between A-Ring and C,D-Ring Parts

A new convergent method for the synthesis of 1α,25 -dihydroxyvitamin D3 and its analogues has been developed that involves efficient preparation of the A-ring part 1a, (Z)-(3S,5R)-1-bromom-ethylene-3,5-bis(tert-butyldimethylsilyloxy) -2-methylenecyclohexane, starting from epichlorohydrin (4) and its Suzuki-Miyaura coupling reaction with the C,D-ring part 12. Thus, (R)-4 was converted to (3S,5R)-5-(tert-butyldimethylsilyloxy)-8-(trimethylsilyl)-oct-l-en-7-yn-3-ol (3a) through a ten-step reaction sequence in 49% overall yield. Compound 3a thus obtained was treated with a Ti(O-i-Pr)4/2 i-PrMgCl reagent and then with NBS to afford (Z)-(1S,2S,5R)-2-bromomethyl-3-[bromo-(trimethylsilyl)methylene] -5-(tert-butyldimethylsilyloxy)cyclohexanol (10a) in 51% yield, from which la was obtained in 87% yield by sequential treatment with TBSCl/imidazole, DBU, and Cs2CO3. The resulting A-ring intermediate 1a was reacted with alkenylboronate 12 in the presence of a PdCl2(dppf) catalyst to furnish 1α,25 -dihydroxyvitamin D3 in 82% yield after protodesilylation. Similarly, all of the other three possible stereoisomers of A-ring parts 1b, 1c, and 1d were prepared, from which 1-epi-, 3-epi-, and 1,3-di-epi-1α,25-dihydroxyvitamin D3 were synthesized by coupling with 12 in excellent yield, respectively. Starting from 1a and 1c, des-C,D-1α,25-dihydroxyvitamin D3 analogues, retiferol 13 and its 3-epi derivative, were also prepared, respectively.