Photoreactions of Succinimides with an N-Acyl Group in the Side Chain. Synthesis and Stereochemistry of Tricyclic Pyrrolo[1,2-α]pyrazine Ring Systems

Photocyclization of succinimides with an N-acyl group in the side chain gave bi- and tricyclic phyrrolo[1, 2-a]pyrazines, some of which were converted to tricyclic amines by reduction. The stereochemistry of pyrrolo[1, 2-a]pyrazine derivatives is discussed on the basis of the results of X-ray analysis and carbon-13 nuclear magnetic resonance spectroscopy.