(1 RS ,3 SR)-1-(4-Methylbenzyl)-7-phenyl-5-oxa-6-azaspiro[2.4]hept-6-en-4-one.

The previously unknown cyclopropane spiro-fused with isoxazol-5-one ((1RS,3SR)-1-(4-methylbenzyl)-7-phenyl-5-oxa-6-azaspiro[2.4]hept-6-en-4-one) was synthesized from benzylideneisoxazol-5-one in 34% yield via double methylene transfer from diazomethane. The structure of the compound was established based on 1H, 13C, and 2D NMR spectroscopy and high-resolution mass spectrometry, and confirmed by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]