1,5-Anhydro-D-fructose from D-fructose

Abstract 1,5-Anhydro- d -fructose was efficiently prepared from d -fructose via regiospecific 1,5-anhydro ring formation of 2,3- O -isopropylidene-1- O -methyl(tolyl)sulfonyl- d -fructopyranose and subsequent deprotection.