Described are total syntheses of O-[sodium (5-acetamido-3,5-dideoxy-D -glycero-alpha-D-galacto-2-nonulopyranosyl)onate]-(2----3)-O -beta-D -galactopyranosyl-(1----1)-(2R,3S,4E)-2-N-tetracosanoylsphingen ine,O-[sodium (5-acetamido-3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosyl+ ++)onate] -(2----3)-O-alpha-D-galactopyranosyl-(1----1)-(2R,3S,4E)-2-N -tetracosanoylsphingenine, O-[sodium (5-acetamido-3