Abstract
Oxidation of 2,3-dihydrofuran or 2,3-dihydropyran with peroxybenzoic acid or m-chloroperoxybenzoic acid in the presence of an alcohol has produced, respectively, trans-2-alkoxy-3-hydroxytetrahydrofurans in 59 to 64% yield and trans-2-alkoxy-3-hydroxytetrahydropyrans in 65 to 80% yield. In the presence of acids, these acetals isomerize readily to give an equilibrated mixture of cis and trans isomers.