ACID-CATALYZED BACKBONE REARRANGEMENT OF CHOLESTA-6,8(14)-DIENES

Authors
LIU RM CHILLIER XFD KAMALAPRIJA P BURGER U GULACAR FO
Citation
Rm. Liu et al., ACID-CATALYZED BACKBONE REARRANGEMENT OF CHOLESTA-6,8(14)-DIENES, Helvetica Chimica Acta, 79(4), 1996, pp. 989-998
Citations number
15
Categorie Soggetti
Chemistry
Journal title
Helvetica Chimica Acta → ACNP
ISSN journal
0018019X
Volume
79
Issue
4
Year of publication
1996
Pages
989 - 998
Database
ISI
SICI code
0018-019X(1996)79:4<989:ABROC>2.0.ZU;2-B
Abstract
Rearrangement of 5 alpha- and 5 beta-cholesta-6,8(14)-dienes (13a and 13b, resp.) in the presence of anhydrous toluene-4-sulfonic acid in ac etic acid leads to 5 alpha- and 5 beta-12(13 --> 14)-abeo-cholesta-8,1 3(17)-dienes (15a and 15b, resp.) via 5 alpha- and 5 beta-cholesta-8,1 4-dienes (14a and 14b, resp.), respectively. Epimerization at C(20) of the spirosteradienes 15a and 15b occurs with increasing reaction time . Molecular-mechanics calculation of the relative stabilities of these compounds and of congeners thereof is in agreement with the observed reaction pathway.