An Efficient Synthesis of endo,exo-Furofuranone Derivatives.

The ring openings of 1-acetyl-4-phenyl-3-oxabicyclo[3.1.0]hexane afforded α-acetyl-γ-butyrolactones that underwent a novel diazo-transfer reaction, followed by C–H insertion, to provide a series of endo,exo-furofuranone analogues.