79998-98-4Relevant academic research and scientific papers
Aza Cope Rearrangements in the Cyclopropenyl-and Allyl-Substituted Δ2-Oxazolinone Systems
Padwa, Albert,Akiba, Mitsuo,Cohen, Leslie A.,MacDonald, Gavin J.
, p. 695 - 703 (2007/10/02)
The scope of the thermal and photochemical reorganization reactions of a number of cyclopropenyl- and allyl- substituted oxazolinones has been examined.These systems undergo a facile sigmatropic rearrangement in accord with orbital symmetry predictions. 2-Methyl-4-allyl-Δ2-oxazolinones were found to undergo a 3,3-sigmatropic allyl shift on thermolysis to give the Δ3-oxazolinone isomer.In contrast, on direct irradiation the 2-methyl-4-allyl-Δ3-oxazolinones undergo a 1,3-allyl shift to give the Δ2-isomer.The 4,4-disubstituted Δ2-oxazolinones undergo decarbonylat ion either on irradiation or by flash vacuum pyrolysis to give acetimides.The acetimides formed were easily hydrolyzed to give the corresponding ketones.The excited-state behavior of the 2-phenyl-4-methyl-Δ2-oxazolinone system was found to be markedly different from that encountered with the 2-methyl-4-phenyl-substituted isomer.The rationale for the difference in behavior is discussed.
