One Pot Synthesis of Cyclobutanols by Ring Expansion of Oxaspiropentanes Induced by Grignard Reagents

BERNARD, ANGELA MARIA;FLORIS, COSTANTINO;FRONGIA, ANGELO;PIRAS, PIER PAOLO

1998-01-01

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Abstract

Aromatic, aliphatic and vinylic Grignard reagents efficiently catalyze the ring expansion of oxaspiropentanes 2a,b to give, in one pot, good yields of cyclobutanols 3a, 3b-7b. Benzyl magnesium chloride gives a mixture of cyclobutanols and the cyclopropanol 8, probably coming from a direct nucleophilic attack on the epoxide part of the oxaspiropentane.