Bismuth triflate-catalyzed Wagner-Meerwein rearrangement in terpenes. Application to the synthesis of the 18α-oleanane core and A-neo-18α-oleanene compounds from lupanes
作者:Jorge A. R. Salvador、Rui M. A. Pinto、Rita C. Santos、Christophe Le Roux、Ana Matos Beja、José A. Paixão
DOI:10.1039/b814448f
日期:——
catalysts for the Wagner-Meerwein rearrangement of lupane derivatives with expansion of ring E and formation of an additional O-containing ring is reported. This process has also been extended to other terpenes, such as the sesquiterpene (−)-caryophyllene oxide. When the reaction was performed with oleanonic acid, 28,13β-lactonization occurred, without Wagner-Meerwein rearrangement. Under more vigorous reaction