Cbz-O-苄基-L-丝氨酸 、 、
N-(9-fluorenylmethoxycarbonyl)-O-[2,3,4,6-tetra-O-benzyl-β-D-galactopyranosyl-(1->3)-2-acetamido-4,6-O-benzylidene-2-deoxy-α-D-galactopyranosyl]-L-threonine 、 N-(9-fluorenylmethoxycarbonyl)-O-[2,3,4,6-tetra-O-benzyl-β-D-galactopyranosyl-(1->3)-2-acetamido-2-deoxy-6-O-(α,α-dimethyl-4-aminobenzyl)dimethylsilyl-α-D-galactopyranosyl]-L-threonine allyl ester 以55%的产率得到