| —— | 
                                        (R)-2-((1R,5R)-3-Benzoyl-7-oxo-4-thia-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-but-3-enoic acid benzyl ester | 
                                        91530-67-5 | 
                                        C25H22N6O4S2 | 
                                        534.619 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (R)-2-[(1R,5R)-3-((R)-Hydroxy-phenyl-methyl)-7-oxo-4-thia-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl]-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-but-3-enoic acid benzyl ester | 
                                        91530-68-6 | 
                                        C25H24N6O4S2 | 
                                        536.635 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (R)-2-[(2R,3R)-2-(Benzothiazol-2-yldisulfanyl)-4-oxo-3-(2-oxo-2-phenyl-acetylamino)-azetidin-1-yl]-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-but-3-enoic acid benzyl ester | 
                                        91775-99-4 | 
                                        C32H27N7O5S4 | 
                                        717.874 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (R)-2-[(2R,3R)-2-(Benzothiazol-2-yldisulfanyl)-3-((R)-2-hydroxy-2-phenyl-acetylamino)-4-oxo-azetidin-1-yl]-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-but-3-enoic acid benzyl ester | 
                                        91530-69-7 | 
                                        C32H29N7O5S4 | 
                                        719.89 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (R)-2-[(2R,3R)-2-(Benzothiazol-2-yldisulfanyl)-3-((S)-2-hydroxy-2-phenyl-acetylamino)-4-oxo-azetidin-1-yl]-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-but-3-enoic acid benzyl ester | 
                                        91603-77-9 | 
                                        C32H29N7O5S4 | 
                                        719.89 |