Nuclear Magnetic Resonance Spectroscopy. Structure and Dynamic Character of Allylic Grignard Reagents

摘要

Studies have been made of the nuclear magnetic resonance spectra of several allylic Grignardudreagents. The Grignard reagent prepared from γ,γ-dimethylallyl bromide appears best formulatedudas an equilibrium mixture of γ,γ-dimethylallylmagnesium bromide and α,α-dimethylallylmagnesiumudbromide, in which the former is the major component. The rate of interconversion of the allylicudisomers is rapid on the n.m.r. time scale at room temperature, but slow at -40°.