Chiral oxetanes from sugar lactones: Synthesis of derivatives of 3,5-anhydro-1,2-O-isopropyl-α-D-glucuronic acid and of 3,5-anhydro-1,2-O-isopropyllidene-β-L-iduronic acid

Ring contraction reactions of triflates of α-hydroxy-γ-lactones provide an approach to the synthesis of chiral polyfunctionalised oxetanes from sugars. Treatment of 1,2-0-isopropylidene-5-0-trifluoromethanesulphonyl-α-D-glucuronolactone with benzylamine or with potassium carbonate in methanol gave ring contraction reactions to form oxetanes in good yield. © 1987.