p. 1381 - 1387
(2007/10/02)(3S,4S)-3-<(1R)-1-hydroxyethyl>-1-(p-nitrobenzyloxycarbonylmethyl)-4-<(1R)-1-phenylthiocarbonylethyl>-2-azetidinone
(3S,4S)-4-<(1R)-1-benzyloxycarbonylethyl>-1-(tert-butoxycarbonylmethyl)-3-<(1R)-1-tert-butyldimethylsilyloxy>-2-azetidinone
(3S,4S)-1-(tert-butoxycarbonylmethyl)-3-<(1R)-1-tert-butyldimethylsilyloxyethyl>-4-<(1R)-1-phenylthiocarbonylethyl>-2-azetidinone
(3S,4S)-1-(tert-butoxycarbonylmethyl)-3-<(1R)-1-tert-butyldimethylsilyloxyethyl>-4-<(1R)-1-carboxyethyl>-2-azetidinone
(3S,4S)-3-[(1R)-1-hydroxyethyl]-4-[(1R)-1-phenylthiocarbonylethyl]-1-carboxymethylazetidin-2-one
p-nitrobenzyl (4R,5S,6S)-3-<(3S,5S)-5-dimethylaminocarbonyl-1-(p-nitrobenzyloxycarbonyl)pyrrolidin-3-ylthio>-6-<(1R)-1-hydroxyethyl>-4-methyl-7-oxo-1-azabicyclo<3.2.0>hept-2-en-2-carboxylate
(4R,5S,6S)-6-((R)-1-Hydroxy-ethyl)-4-methyl-7-oxo-3-[4-(1,2,3,4-tetrahydro-isoquinolin-7-yl)-thiazol-2-ylsulfanyl]-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester
(4R,5S,6S)-6-((R)-1-Hydroxy-ethyl)-4-methyl-3-(4-{4-[(4-nitro-benzyloxycarbonylamino)-methyl]-phenyl}-thiazol-2-ylsulfanyl)-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester