Aldol reaction of reducing sugars. Convenient stereoselective synthesis of ribofuranosylacetone and chiral dienones

Abstract

Aldol reaction of 2,3-O-isopropylidene-D-ribose with acetone, catalysed by aqueous K₂CO₃, gave 1(2,3-O-isopropylidene-α-D-ribofuranosyl)acetone. Similar reactions of 2,3,5-tri-O-benzyl-D-ribofuranose, 2,3,4,6-tetra-O-benzyl-D-gluco- and -D-galactopyranose afforded chiral (3E,5Z,7S)-octa 3,5-dien-2-one, (3E,5Z,7S,8R)-nona-3,5-dien-2-one, and (3E,5Z,7R,8R)-nona-3,5-dien-2-one derivatives, respectively.