Grignard reagents reaction with oxiranes

B Reactions of Grignard Reagents WITH OXIRANES (EPOXIDES)... 

Reactions of Oxiranes A. Reaction with Grignard Reagents... 

In a side-chain containing a double-bond 3 to the oxirane, double-bond migration has also been observed. The effects of the solvent and the reagent have been examined in the reaction of vinyl-magnesium bromide and phenyloxirane. Acetylenic oxirane gives a complicated mixture of products with a Grignard reagent, but the Cu halide-catalyzed reaction leads to an allene alcohol (Eq. 

The reaction of alkyllithium with oxirane yields the same products as in the reaction with the Grignard reagent (Eq. 283). 

Fujisawa [67] found that the stereoselective introduction of a prenyl alcohol moiety, with an -configuration, into a vinyl oxirane was readily achieved by a copper-catalyzed 8 2 reaction. Thus, addition of a Grignard reagent 160 to a solution of isoprenyl oxirane and copper(I) iodide (5 mol%) in THF/Me2S (20 1) at — 20"C afforded the allylic alcohol 161 in 95% yield in a 97 3 F/Z ratio [Eq. (54)]. 

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