The Baeyer-Villiger (B.V.) reaction using SeO2-H2O2 was examined for various benzaldehydes possessing methoxy groups and/or a furan ring. When benzaldehydes have an electron-donating group(methoxy group)at the ortho or para position to a formyl group, the B.V. reaction proceeded rapidly and in a good yield. Since the reaction using SeO2-H2O2 is carried out under a neutral condition, this reaction are applicable to aldehyde derivatives with a furan ring which is unstable against acid.
