3(S)-benzyloxycarbonylamino-2,3,4,5-tetrahydro-1,5-benzoxazepine-4-one

tert-butyl (S)-3-amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetate

ethyl 4-cyclohexyl-2-oxo-butyrate