Mesomorphic derivatives of the 6-amino-6-deoxy-D-galactose

Abstract

Amides and sulfonamides of 6-amino-6-deoxy-D-galactose have been synthesized from fatty acids and sulfonic acids with long alkyl chains. A key intermediate of the reaction with the different acids was the 6-amino-6-deoxy-1,2;3,4-di-O-isopropylidene-α-D-galactopyranose. De-isopropylidination of the protected compounds was achieved using trifluoroacetic acid. Molecules with three long alkyl chains can be obtained by reaction of 6-octadecanoylamido-6-deoxy-D-galactose with dodecanethiol. 6-Octadecanoylamido-6-deoxy-D-galactose di-dodecyl dithioacetal exhibits a monotropic hexagonal columnar disordered phase, D_hd, and a rectangular columnar disordered phase, D_rd.