81570-20-9Relevant articles and documents
An asymmetric synthesis of a 1α,25-dihydroxyvitamin D3 A-ring synthon
Chen,Crich
, p. 1945 - 1948 (1992)
An efficient asymmetric synthesis of the A-ring of 1α,25-dihydroxyvitamin D3 from α-bromoacrolein is described. The key steps of the synthesis are the Evans type syn-selective asymmetric aldol reaction of bromoacrolein with the boron enolate of
An efficient enantioselective synthesis of 1α,25-dihydroxyvitamin D3 A-ring synthon
Koiwa, Masakazu,Hareau, Georges P.J.,Sato, Fumie
, p. 2389 - 2390 (2007/10/03)
The asymmetric synthesis of the A-ring of 1α,25-dihydroxyvitamin D3, (Z)-2, from 5-tert-butyldimethylsiloxy-2-cyclohexenone [(S)-1], is described where an intramolecular lactonization using cat. scandium triflate is the key reaction. (C) 2000 Elsevier Science Ltd.
An Efficient Asymmetric Synthesis of 1α,25-(OH)2 Vitamin D3 A-Ring Synthon
Nagasawa, Kazuo,Ishihara, Hideki,Zako, Yoshiro,Shimizu, Isao
, p. 2523 - 2529 (2007/10/02)
Chiral synthesis of the A-ring synthon 3 of 1α,25-dihydroxyvitamin D3 (1a) based on palladium-catalyzed cyclization of 8-bromo-2,8-nonadienoates is described.Reaction of (E)-4b and (Z)-4d in the presence of Pd(OAc)2, PPh3 and K2CO3 gave (E)-3b and (Z)-3d, respectively.Optically active 4d was prepared from 24 by asymmetric aldol reaction using 31, which was cyclized to 3d.With further reactions, 1α,25-dihydroxyvitamin D3 (1a) was obtained.
