Synthesis and Structure of (<i>E</i>)-3-Phenylmethylene-2-oxetanone: Comments on the Stability of Methylene β-Lactones

Abstract

A route to stereospecifically (E)-substituted methylene-2- oxetanones is exemplified by the preparation of the phenyl deriva- tive 4, whose structure has been confirmed by a single crystal X-ray structure determination. The relative stability of the parent com- pound, 3-methylene-2-oxetanone (5) has been compared with that of the well-known 4-methylene-2-oxetanone (6), (ketene dimer) by use of calculations involving Gaussian 82 programs.