1-Phenyl-3-oxabicyclo[3.1.0]hexan-2-one

It features a compact oxabicyclic framework incorporating a lactone (cyclic ester) functionality fused to a cyclopropane-like ring, with a phenyl substituent that adds aromatic character and stability. The inherent ring strain and electrophilic carbonyl group make the molecule highly reactive toward ring-opening, nucleophilic addition, and rearrangement reactions. 1-Phenyl-3-oxabicyclo[3.1.0]hexan-2-one is a strained bicyclic lactone used as a synthetic intermediate in organic and medicinal chemistry.