Agathocleous, D., Cox, Graham and Page, Michael I. (1986) Stereochemistry and ring opening of a carbocyclic analogue of a 1-oxapenam. Tetrahedron Letters, 27 (14). pp. 1631-1634. ISSN 0040-4039

The cycloaddition of succinimido ketene to 2,3-dihydrofuran yields P- -succinimido bicyclo [3.2.0] 2-oxoheptan-6-one. This unusual stereochemistry is confirmed by 1H NMR and X-ray crystallography. The cyclobutanone product undergoes ring opening in concentrated hydrochloric acid to give 1-succinimido-5-chloro-2-pentanone.