p. 1532 - 1537
(1999)methyl (2RS,4R)-2-[(1R,4R)-4-benzyloxycarbonylamino-4-carboxy-1-methylbutyl]thiazolidine-4-carboxylate
methyl (3R,6S,9R,9aR)-6-benzyloxycarbonylamino-9-methyl-5-oxooctahydroazepine[2,1-b]thiazole-3-carboxylate
methyl (2RS,4R)-2-[(1R,4S)-4-diphenylmethoxycarbonyl-4-benzyloxycarbonylamino-1-methylbutyl]thiazolidine-4-carboxylate