TY - JOUR
T1 - An efficient asymmetric synthesis of 1α,25-(OH)2 vitamin D3 A-ring synthon
AU - Nagasawa, Kazuo
AU - Ishihara, Hideki
AU - Zako, Yoshiro
AU - Shimizu, Isao
PY - 1993
Y1 - 1993
N2 - 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.
AB - 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.
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M3 - Article
AN - SCOPUS:0027318462
SN - 0022-3263
VL - 58
SP - 2523
EP - 2529
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
IS - 9
ER -