Solid-phase synthesis of serglycin glycopeptides on a new allyl ester linker

t-Butyl 6-bromo-(E)-4-hexenoate was used as a handle for the solid-phase synthesis of glycopeptides. The handle was first conjugated with Fmoc amino acids to form the allyl esters, which were then attached to the Sieber amide resin via acidic cleavage of the t-butyl esters followed by activation of the liberated carboxylic acids. Solid-phase synthesis was demonstrated for the glycopeptide oligomers modeled after glycosyl Ser-Gly repeating sequence of proteoglycan.