SUCCESSFUL ASYMMETRIC DIELS-ALDER APPROACH TO OPTICALLY ACTIVE C-NUCLEOSIDES. ENANTIOSELECTIVE TOTAL SYNTHESIS OF D-SHOWDOMYCIN AND D-2, 5-ANHYDROALLOSE DERIVATIVES

Abstract

Using an asymmetric Diels-Alder reaction of (S)_S-3- (2-pyridylsulfinyl) acrylate with furan, a highly enantioselective synthesis of a common key intermediate (+) - (1) was achieved, and this was successfully converted to C-nucleosides, D-showdomycin (2) and D-3, 4-O-isopropylidene-2, 5-anhydroallose (3).