| —— | 
                                        (3S,4S)-3-<(R)-1'-(dimethyl-t-butylsilyloxy)ethyl>-4-oxoazetidine-2-carboxylic acid | 
                                        85253-97-0 | 
                                        C12H23NO4Si | 
                                        273.404 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        <3S-<3α(S*),4β>>-3-(1-t-butyldimethylsilyloxyethyl)-4-hydroxymethyl-2-azetidinone | 
                                        81902-63-8 | 
                                        C12H25NO3Si | 
                                        259.421 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        <3S-<3α(S*),4β>>-methyl 3-(1-t-butyldimethylsilyloxyethyl)-2-azetidinone-4-carboxylate | 
                                        84362-40-3 | 
                                        C13H25NO4Si | 
                                        287.431 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        <3S-<3α(S*),4β>>-3-(1-t-butyldimethylsilyloxyethyl)-4-iodomethyl-2-azetidinone | 
                                        84362-42-5 | 
                                        C12H24INO2Si | 
                                        369.318 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (3S,4S)-3-<(R)-1-(t-butyldimethylsilyloxy)ethyl>-4-cyano-2-azetidinone | 
                                        84362-39-0 | 
                                        C12H22N2O2Si | 
                                        254.404 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (3S,4S)-3-<(R)-1-(t-butyldimethylsilyloxy)ethyl>-4-(p-tolylsulfonyloxymethyl)-2-azetidinone | 
                                        84362-41-4 | 
                                        C19H31NO5SSi | 
                                        413.61 |