The first enantioselective synthesis of (−)-microbiotol and (+)-β-microbiotene
作者:Adusumilli Srikrishna、Shankarnarayan A. Nagamani、Setti G. Jagadeesh
DOI:10.1016/j.tetasy.2005.03.009
日期:2005.5
The first enantioselective total synthesis of (-)-microbiotol and (+)-beta-microbiotene, sesquiterpenes containing three neighboring quaternary carbon atoms belonging to the cyclocuparane group, starting from cyclogeraniol employing a Sharpless-Katsuki asymmetric epoxidation, a boron trifluoride etherate mediated epoxide rearrangement and ail intramolecular diazo ketone cyclopropanation as key steps, is described. (C) 2005 Elsevier Ltd. All rights reserved.
A novel boron trifluoride etherate mediated deep-seated rearrangement of an α,β-epoxyketone
作者:Adusumilli Srikrishna、Sripada S.V. Ramasastry
DOI:10.1016/j.tetasy.2005.07.030
日期:2005.9
of carvone epoxide 2 resulted in dimeric products 3 and 4, in contrast to the expected ring contraction product. Reaction of β-methylcarvone epoxides 8 and 11 with acids furnished 2-acetyl-4-isopropenylcyclopentanones 9 and 14 containing a stereodefined quaternary carbon atom. On the other hand, the reaction of epoxides 8 and 11 with borontrifluorideetherate lacks the stereoselectivity and in addition