FLEXIBLE AND STEREOSELECTIVE CONSTRUCTION OF POLYPROPIONATE CHAINS FROM ENANTIOMERICALLY PURE GAMMA-HYDROXY-ALPHA,BETA-UNSATURATED SULFONES

Following an homologation sequence the readily available enantiomerically pure gamma-hydroxy vinyl sulfone 2 has been transformed, with complete control of the stereochemistry, into gamma-hydroxy vinyl sulfones of polypropionate structure. The four stereotriads have been prepared by stereoselective additions of organometallics to the vinyl sulfone moiety and by stereoselective reduction of beta-hydroxyketones. In a similar way, these triads are the substrates for the stereoselective introduction of the fourth consecutive asymmetric center.