(2R,5S)-2-Trichloromethyl-3-oxa-1-azabicyclo[3,3,0]octane-4-one

0]octane-4-one ; 5s)-2-trichloromethyl-3-oxa-1-azabicyclo[3 ; (3r)-trichloromethyl-cis-tetrahydropyrrolo[1,2-c]oxazol-1-one ; (2r, 5s)-2-trichloromethyl-3-oxa-1-azabicyclo[3,3,0]octane-4-one ; (2r,5s)-2-trichloromethyl-1-aza-3-oxabicyclo-[3,3,0]-octam-4-one ; (3r,7as)-3-(trichloromethyl)-hexahydropyrrolo[1,2-c][1,3]oxazol-1-one ; (2r,5s)-2-trichloromethyl-3-oxa-1-azabicyclo[3.3.0]octan-4-one ; (3r,7as)-3-(trichloromethyl)tetrahydropyrrolo[1,2-c]oxazol-1(3h)-one ; l-proline - chloral condensation product ; (3r,7as)-3-(trichloromethyl)tetrahydro-1h,3h-pyrrolo[1,2-c]oxazol-1-one