The tandem oxidation/Wittig olefination of unactivated diols utilizing manganese dioxide produces α, β-unsaturated hydroxy esters in high yields in a highly effective desymmetrization process. The formation of small quantities of the corresponding lactones suggests that the reaction may proceed through a lactol intermediate in some cases. The α, β-unsaturated hydroxy esters are transformed into symmetrical or unsymmetrical dienyl ...
