(3R,4S)-1-t-butoxycarbonyl-3-(2-ethoxyethoxyl) -4-phenyl-2-azetidinone CAS: 201856-57-7 Formula: C18H25NO5 purity 98% optical purity 99% (3R,4S)-1-benzoyl-3-(2-ethoxyethoxyl) -4-phenyl-2-azetidinone CAS: 201856-53-3 Formula:C18H25NO5 purity 98% optical purity 99% (3R,4S)-1-t-butoxycarbonyl-3-triethylsilyloxy -4-phenyl-2-azetidinone CAS: 149198-47-0 Formula: C20H31NO4Si purity 98% optical purity 99% (3R,4S)-1-benzoyl-3-triethylsilyloxy -4-phenyl-2-azetidinone CAS:149249-91-2 Formula: C22H27NO3Si purity 98% optical purity 99% (3R,4S)-1-t-butoxycarbonyl-3-acetoxy -4-phenyl-2-azetidinone Formula: C16H19NO5 purity 98% optical purity 99% (3R,4S)-1-benzoyl-3-acetoxy -4-phenyl-2-azetidinone Formula: C18H15NO4 purity 98% optical purity 99% (2R,3S)-3-t-butoxy-carbonylamino-2-hydroxy-3-phenylpropionacid CAS:145514-62-1 Formula: C14H19NO5 purity 98% optical purity 99% (2R,3S)-3-benzoylamino-2-hydroxy-3-phenylpropionacid CAS:132201-33-3 Formula: C16H15NO4 purity 98% optical purity 99%