1,3-Dipolar cycloreversion of a 1,3,4-oxadiazolidine as a controlled azomethine imine surrogate for pyrazolidine synthesis

Article abstract of DOI:10.1016/0040-4039(96)00836-2

Azomethine imines were generated in a controlled manner through a thermally allowed 1,3-dipolar cycloreversion of 1,3,4-oxadiazolidines and subsequently trapped with dipolarophiles. This method results in the construction of the pyrazolidine heterocycles. A new method for the selective formation of the key semicarbazide substrate, from benzylidene hydrazone, is also disclosed.