p. 2973 - 2976
(2007/10/03)p. 210 - 220
(2007/10/03)p. 4221 - 4224
(2007/10/02)trifluoromethylsulfonic anhydride
4-nitrobenzyl (2R,5R,6S)-6-[(1R)-1-hydroxyethyl]-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylate
(5R,6S)-6-(1-Hydroxy-ethyl)-3,7-dioxo-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid 4-nitro-benzyl ester
(5R,6S)-6-[(R)-1-hydroxyethyl]-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylic acid p-nitrobenzyl ester