SYNTHESIS OF THE BUILDING-BLOCKS (3)GALN(3)P-(1-]3)-ALPHA-D-AC(2)GALN(3)P]-THR-OPFP AND (3)GALN(3)P-(1-]6)-ALPHA-D-AC(2)GALN(3)P]-THR-OPFP AND THEIR APPLICATION IN THE SOLID-PHASE GLYCOPEPTIDE SYNTHESIS OF CORE-5 AND CORE-7 MUCIN O-GLYCOPEPTIDES

The structures alpha-D-GalNAc-( 1-->3)-alpha-D-GalNAc-(1-->O)-L-Thr an d lpha-D-GalNAc-(1-->6)-alpha-D-GalNAc-(1-->O)-L-Thr are present as co res 5 and 7 of the mucin-type glycoproteins. The preparation of the co rresponding building blocks 10 and 15 is described. Compounds 10 and 1 5 can be used directly in a multiple-column solid-phase glycopeptide p eptide synthesis. In the resulting peptides the azido groups are reduc ed and acetylated on the solid support. The products are cleaved from the resin and the carbohydrate part is deprotected. A series of 20 O-g lycopeptides has been prepared.