Metalated epoxides as carbenoids. Competing C–H and CC insertion in α-alkoxy epoxide systems
摘要:
In a reinvestigation of the reactivity of carbenoids derived from epoxides, we studied the factors that could influence the chemoselectivity of the carbenoid insertion into vicinal C-H or C=C bond in cyclic alpha-alkoxy epoxides bearing an alkenyl side chain. This reaction gives access to bi- or tricyclic systems, respectively. (C) 2003 Elsevier Ltd. All rights reserved.
Intramolecular cyclopropanation reaction of β-γ-unsaturated epoxides yields highly strained tricyclo[4,1,0,01,5]heptane compounds whose hydrolysis affords α-keto spiro cyclopropanes. Both steps of this one-pot reaction are stereospecific.