Y. Ogata, K. Takagi
1971
Citations
0
Influential Citations
8
Citations
Journal
Tetrahedron
Abstract
Abstract Irradiation of 1-alkyl-3,4-dihydroisoquinolines( Ia, b ) containing γ-hydrogen afforded 1-methyl-3,4-dihydroisoquinolines( IIa, b ) in poor yields. The elimination is analogous to the type II cleavage of ketone. The similarity between this photoreaction and the electron-impact fragmentation was observed. Ethyl 3,4-dihydroisoquinoline-1-acetate( Ic ) without γ-hydrogen is stable photochemically in an inert solvent, but it was readily photodecomposed to yield IIa in a good yield in excess HCl aq. Ic is stable in the dark at room temperature, but Ic decomposes quantitatively into IIa by refluxing 50° HCl aq. A reaction pathway is presented and discussed.