Simultaneous formation of isoquinoline and 1-azetine derivatives via photoacetyl migration of substituted α-dehydrophenylalanine

Abstract Irradiation of substituted α-dehydrophenylalanine in methanol or acetonitrile with Pyrex-filtered light was found to give isoquinoline and 1-azetine derivatives in relatively good yields, which may be formed via 1,5-acetyl shift from the ( Z )-isomer and 1,3-acetyl migration from the ( E )-isomer, respectively. The photoreaction in methanol afforded the azetine in preference to the isoquinoline, while the reverse result was obtained in acetonitrile.