Spacered terminal disaccharide of Forssman's antigen GalNAc alpha 1-3GalNAc beta 1-Osp, its analog GalNAc alpha 1-3GalNAc alpha 1-Osp, and disaccharides Gal beta 1-3GalNAc beta 1-Osp and Gal alpha 1-3GalNAc alpha 1-Osp [where sp denotes the (CH2)3NHCOCF3 spacer] were synthesized. Spacered disaccharides were obtained from the (3-trifluoroacetamidopropyl)-2-acetamido-4,6-O-benzylidene-2-deoxy-beta-D- galactopyranoside and its alpha- and beta-analogs in which the 2-azido group was substituted for the 2-acetamido group. The azide glycosyl acceptors gave higher yields of the disaccharides. Azide glycosyl acceptors were prepared by the stereoselective glycosylation of 3-trifluoroacetamidopropanol with a mixture of 1-O-acetates of the 2-azido-3,4,6-tri-O-acetyl-2-deoxy-D-galactopyranose anomers in the presence of Lewis acids. Disaccharides Gal alpha 1-3GalNAc and GalNAc alpha 1-3GalNAc were obtained from the benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-galactopyranoside.