These structures have oligosaccharides attached to the ceramide moiety. The structures are synthesized in a stepwise manner. First a glucose or galactose residue is attached to the C-1 hydroxyl of ceramide from the activated UDP-sugar. Then activated sugar residues (UDP-glucose, UDP-galactose, UDP-N-acetylgalactosamine, and a CMP derivative of N-acetylneuraminate) are added to form the oligosaccharide.