Studies on Organic Fluorine Compounds. XLVII. Synthesis of Trifluoromethylated Sugars through the Aldol Reaction of 2-Trimethylsilyloxy-4-trifluoromethylfuran

Abstract

Lewis acid-catalyzed aldol condensation of 2-trimethylsilyloxy-4-trifluoromethylfuran (2a) with aldehydes was found to proceed in a regio- and diastereoselective manner to give the 5-substituted 4-trifluoromethyl-2 (5H)-furanone (4) in good yield. The aldol product (4a) derived from benzyloxyacetaldehyde was successfully converted to the branched sugar (12), the first reported example of a trifluoromethylated branched sugar, and its crystal structure was determined by X-ray analysis.