Baeyer–Villiger rearrangement of polyalkoxybenzaldehydes with benzene ring opening

The Baeyer–Villiger oxidation of apiolaldehyde bearing o-(3-p-anisylisoxazolin-5-yl)methyl substituent proceeds first with the formation of the anticipated phenol. The subsequent oxidation of phenol with destruction of methylenedioxy ring leads to p-quinone derivative which would undergo opening of the benzene ring to finally produce maleic anhydride moiety. The structure of new compounds was proved by X-ray diffraction analysis.