NEW METHOD FOR CONVERTING OXIRANES TO ALLYLIC ALCOHOLS BY AN ORGANOSILICON REAGENT

The oxirane to allylic alcohol isomerization (eq 1) is an essential operation in organic synthesis and a variety of reagents have been elaborated for this purpose. The recently discovered dialkylaluminum amides1 and a dialkylboron trifluoromethanesulfonate2 are applicable to the reaction of trans-2, 3-dialkylated oxiranes (but not cis or common cyclic derivatives) or further alkylated substrates. The conversion of oxiranes derived from five- to seven-membered cyclic olefins may be effected by strongly basic lithium amide reagents in re-fluxing solvents.3 A mild, two-step procedure via an organo-selenium reagent was also developed; nucleophilic displacement of oxiranes with sodium phenylselenide followed by hydrogen peroxide oxidation of the resulting hydroxy selenides, causing elimination of phenylselenic acid, affords the desired allylic alcohols.4 We here disclose a new procedure based on the use of an organosilicon compound. This method requires only very mild reaction conditions and is employable satisfactorily to the reaction of cyclic substrates as well as 2, 2-di. © 1979, American Chemical Society. All rights reserved.