Zr[bis(salicylidene)ethylenediaminato]-mediated Baeyer-Villiger oxidation: stereospecific synthesis of abnormal and normal lactones.

ABSTRACT: Baeyer-Villiger oxidation of racemic bicyclic cyclobutanones with Zr[bis(salicylidene)ethylenediaminato] (salen) complex 1 as catalyst in the presence of a urea-hydrogen peroxide adduct was found to proceed enantiospecifically. The enantiotopos selection in the oxidation was governed primarily by the Zr(salen) catalyst, although migratory aptitude (methine > methylene > methyl) in Baeyer-Villiger oxidation affected the selection to a varied extent, depending on the substrate structures; one enantiomer of cyclobutanones gave exclusively a normal lactone expected from the migratory aptitude, and the other enantiomer gave an abnormal lactone preferentially, the formation of which is counter to the migratory aptitude. Furthermore, the rates of abnormal lactone formation were found to be faster

SUBMITTER: Watanabe A 

PROVIDER: S-EPMC395977 | biostudies-literature | 2004 Apr

REPOSITORIES: biostudies-literature