356527-82-7Relevant academic research and scientific papers
Mechanistic considerations on the oxime-nitrone isomerization and intramolecular cycloaddition reaction of 3-(Alk-2-enylamino)propionaldehyde oximes
Noguchi,Kakehi,Okada,Tanaka,Matsumoto,Kakehi,Yamamoto
, p. 917 - 925 (2001)
To elucidate the scope and features of the intramolecular oxime olefin cycloaddition in the 3-(alk-2-enylamino)propionaldehyde oximes, four 3-(N-substituted allylamino)propionaldehyde oximes were prepared and their thermal behaviors in protic and aprotic solvents (n-butanol and toluene) were studied. To better understand the isomerization process of oxime to NH-nitrone, the thermal reaction of 3-(N-substituted cinnamylamino)propionaldehyde oximes in ethanol or toluene was examined, in which the formation of cyclic nitrone could be interrupted due to steric and/or electronic grounds. Under mild conditions, 3-(alk-2-enylamino)- and 3-(acryloylamino)-2,2-dimethylpropionaldehyde oximes underwent thermally induced 1,3-dipolar cycloaddition, resulting in perhydroisoxazolo[4,3-c]pyridine derivatives. The activation enthalpy in the conversion of N-benzyl oxime indicated that the geminal methyl groups at the 2-position in this oxime should be insufficient to control its conformation necessary for the oxime-nitrone isomerization and/or the intramolecular cycloaddition step of the resulting NH-oxime.
