Preparation of core 2 type tetrasaccharide carrying decapeptide by benzyl protection-based solid-phase synthesis strategy

b-D-Gal-(1-->4)-beta-D-GlcNAc-[beta-D-Gal-(1-->3)]-alpha-D-GaINAc-(1-->3)-L-Ser/Thr building blocks for solid-phase synthesis of glycopeptide were stereoselectively synthesized in a benzyl-protected form. The key glycosylation reaction to form beta-D-GlcNAc linkage was established by the use of protected N-trichloroacetyl-D-lactosaminyl fluoride. Usefulness of the building block was demonstrated by solid-phase synthesis of a segment of human leukosialin. Benzyl protecting group was efficiently removed by 'low acidity TfOH' conditions. (C) 2002 Elsevier Science Ltd. All rights reserved.