p. 599 - 603
(2007/10/02)(6R)-7t-benzoylamino-7c-methoxy-3-methyl-8-oxo-(6rH)-5-oxa-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydryl ester
(6R)-7c-benzoylamino-3t-bromo-3c-methyl-8-oxo-(6rH)-5-oxa-1-aza-bicyclo[4.2.0]octane-2c-carboxylic acid benzhydryl ester
(2S,3S)-3-bromo-4-hydroxy-3-methyl-2-((1R)-7-oxo-3-phenyl-(1rH,5cH)-4-oxa-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-butyric acid benzhydryl ester
(6R)-7c-benzoylamino-3c-hydroxy-3t-methyl-8-oxo-(6rH)-5-oxa-1-aza-bicyclo[4.2.0]octane-2c-carboxylic acid benzhydryl ester
(2R,3Ξ)-3,4-dihydroxy-3-methyl-2-((1R)-7-oxo-3-phenyl-(1rH,5cH)-4-oxa-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-butyric acid benzhydryl ester
(6R,7R)-7-[5-tert-Butoxycarbonylamino-5-(2,2,2-trichloro-ethoxycarbonyl)-pentanoylamino]-7-methoxy-3-methyl-8-oxo-5-oxa-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydryl ester
(6R,7R)-7-(5-tert-Butoxycarbonylamino-5-carboxy-pentanoylamino)-7-methoxy-3-methyl-8-oxo-5-oxa-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydryl ester