B. P. Pradhan, S. Chakraborty, P. Weyerstahl
1987
Citations
0
Influential Citations
9
Citations
Journal
Tetrahedron
Abstract
Abstract Hydrogen peroxide-selenium dioxide in t -butanol has been found to be a good reagent for the preparation of 11α,12α, -oxidotriterpenoids of oleanane and ursane skeletons; whereas α -amyrin and β-amyrin acetates furnished 11α,12α -epoxyurs-14-en-3β-yl acetate ( 4c ) and 11α, 12α -epoxytaraxer-14-en-3β-yl acetate ( 4a ) respectively, uvaol and ursolic acid/methyl ester gave 11α, 12α -epoxyurs-28→13-olide-3β-ol ( 5d ); erythrodiol ( 3c ) and oleanolic acid ( 3b )/methyl ester ( 3d ) afforded 11α, 12α-epoxy-oleanam-28→13-olide-3β-ol ( 5 ) ; oleam-12-en-2α, 3β, 28-yl triacetate ( 3j ) on similar reaction furnished 11α, 12α -epoxytaraxer-14-en-3β-ol-2α, 28-yl diacetate ( 4d ) and 11α, 12α-epoxytaraxer-14-en-2α,3β-diol-28-yl acetate ( 4e ).