Tandem Three-Component Synthesis of syn-1,2- and syn-1,3-Diol Derivatives.

The development of efficient methods for stereocontrolled synthesis of polyol derivatives has been of continuing interest for the synthetic community. We describe herein tandem olefin cross-metathesis/hemiacetalization/intramolecular oxa-Michael addition of allylic/homoallylic alcohols, α,β-unsaturated ketones, and aldehydes, which enabled the synthesis of syn-1,2- and syn-1,3-diol derivatives in a step-economical manner. A series of differentially protected polyol derivatives could be obtained in subsequent transformations via chemoselective/regioselective cleavage of the acetal moiety of the tandem reaction products.