PHOTOCHEMISTRY OF 3-BENZOYL-DELTA(2)-ISOXAZOLINES AND 2-PHENYL-3-BENZOYLISOXAZOLIDINES

The irradiation of 3-benzoyl-Delta(2)-isoxazolin-5-carboxylic acid-eth ylester and its chlorobenzoylderivatives 1a-c with monochromic light ( lambda(ecx) = 254nm acid 365nm) gives in all cases a mixture of produc ts. The quantum yields of the photolysis (lambda(ecx) = 254nm) for 1a- c are in range of phi approximate to 10(2) in oxygen saturated solutio n and phi = 10(-1) in argon saturated solution. The quantum yields of the photoreaktions of 2-phenyl-3-benzoylisoxazolidin-5-carboxylic acid -ethylester and its chlorobenzoylderivatives 2a-c (lambda(ecx) = 254nm ) are quite small (phi approximate to 0,001) and do not depend on solv ent and oxygen. Mechanistical investigations (GC-MS, Laserphotolysis, low temperature-ESR) show that 1a-c behaves like alpha-diketones and 2 a-c like alpha-aminoketones.