The Behavior of 2-Acetamido-2-deoxy-o-galactose with Isopropenyl Acetate in the Presence of p-Toluenesulfonic Acid. Formation of an Unsaturated Aminosugar Derivative

Abstract

Treatment of 2-acetamido-2-deoxy-n-galactose (III) with isopropenyl acetate and p-toluenesulfonic acid gives 2-(n-glycero-1,2- -diacetoxyethyl)-4-(N-acetylacetamido) furan (II), the anomeric 1,3, 4,6-te tra-O-acety 1- 2-(N -acetylacetamido )-2-d eoxy-o-gala ctopyranoses (IV and V), a mixture of the anomeric 1,3,5,6-te tra-0-acetyl-2- -(N-acetylacetamido) -2- deoxy-o-galactofuranoses (VII) and 1,4,6 - -tri -O-acetyl-2-(N-acetylacetamido)-2 ,3-dideoxy-o-threo-hex-2-enopyranose (X) . The anomeric 2-acetamido-1,3,4,6 -tetra-O-acetyl-2- -deo xy-n-galactopyranoses (VI) were also d etected ; they may be primary products or artifacts arising from IV and V by spontaneous de-N-acetylation in the course of the chromatography w hich was used