(3R,5R,6S)-6-(2-benzyloxy-benzoylamino)-3,5,7-tris-(tert-butyl-dimethyl-silanyloxy)heptanoic acid methyl ester

(3R,5R,6S)-6-(2-benzyloxybenzoylamino)-3,5,7-tris-(tert-butyldimethylsilanyloxy)heptanoic acid

(3R,4S)-5-benzyloxy-4-benzyloxycarbonylamino-3-(tert-butyl-dimethyl-silanyloxy)pentanoic acid methyl ester

(3R,4S)-5-benzyloxy-4-benzyloxycarbonylamino-3-(tert-butyl-dimethyl-silanyloxy)pentanoic acid

(5R,6S)-7-benzyloxy-6-benzyloxycarbonylamino-5-(tert-butyl-dimethyl-silanyloxy)-3-oxoheptanoic acid methyl ester