Abstract
Convenient syntheses of 1, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo[2, 3-α]quinolizine derivatives (4a, b) and a relatd unsaturated lactam (14) are described. The condensation of tryptamine (1) with 8a, b (prepared from 7a, b by decarboethoxylation), followed by treatment with alkali gave the lactams (4a, b), respectively. The stereochemistry of 4b was determined by conversion to the known cis- and trans-compounds (5b). The condensation of 1 with the sulfenylated ester (10), which was prepared in two ways, followed by treatment with alkali gave the lactams (12a, b). Oxidation of 12a, b with m-chloroperbenzoic acid gave the sulfoxides (13) which were heated at 50°C to give the lactams (14, 15) and the pyridone (16).
