SYNTHESIS OF ALPHA-BIOTINYLATED AND BETA-BIOTINYLATED T-ANTIGEN

The T-antigen [beta-D-Gal-(1 --> 3)-D-GalNAc] has been linked to bioti n through a C-6 spacer arm for the detection of a specific 'T-antigen- lectin' complex at the surface and/or on the migration pathway of mela noma cells. When 4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha- or -beta-D-galactopyranosyl halides were treated with N-benzyloxycarbony l or N-fluorenylmethoxycarbonyl protected aminohexanols (used as the s pacer arm), unusual stereoselectivities were observed for the synthesi s of the alpha and beta anomers. The synthesis of the alpha anomer cou ld only be achieved, in reasonable yields, with the Schiff base of ami nohexanol. (C) 1997 Elsevier Science Ltd.