Abstract
On irradiation in an aqueous solution, N-chloroacetyl-2, 5-dimethoxyphenethylamine (1) gave 6, 9-dimethoxy-1, 2, 4, 5-tetrahydro-3H-3-benzazepin-2-one (2), 7-hydroxy-1, 2, 4, 5-tetrahydro-3H-3-benzazepin-2-one (4), 4-methoxy-1-azatricyclo[6, 2, 1, 04, 11]undeca-5-ene-2, 7-dione (7) and 11-methoxy-1-azatricyclo[6, 2, 1, 04, 11]undeca-7-ene-2, 6-dione (8). The structure of 2, 4 and 8 were determined by their spectral data. Compound 7 has also nicely assignable spectra except the ultraviolet spectrum in which no π-π band of the enone group appears above 200 nm. However, the structure of 7 has been confirmed through the conversion to pyrroloindole derivatives (11, 13, 14) and the deuterium exchange reaction. Compound 8 also gave other pyrroloindole derivatives (16, 17). The mechanism of these rather unusual photocyclizations were finally discussed.
