Synthesis of higher-carbon sugars via cross-aldolization of 7-oxanorbornan-2-one and carbohydrate aldehyde derivatives

Abstract

The TiCl4-induced condensation of (+)-(1S,4S,5S,6S)-5,6-isopropylidenedioxy-2-t-butyldimethylsilyloxy-7-oxabicyclo[2.2.1]hept-2-ene with 2,3-O-isopropylidene-D-glyceraldehyde was highly stereoselective, giving a product that was converted with high stereoselectivity into protected D-erythro-D-talo-octose and D-erthro-L-allo-octose.