SYNTHESIS OF 12-METHYL-1,2,3,4,6,7,12,12B-OCTAHYDROINDOLO [2,3-A]QUINOLIZINE (1), 1-BENZOYL-1,2,3,4,6,7,12,12B-OCTAHYDROINDOLO [2,3-A]QUINOLIZINE (2), AND 1-PHENYLCARBINOL-1,2,3,4,6,7,12,12B-OCTAHYDROINDOLO [2,3-A]QUINOLIZINE (3)

12‐Methyl‐l, 2, 3, 4, 6, 7, 12, 12b‐octahydroindolo[2, 3‐a]quinolizine (1) is synthesized through a new route developed in our laboratory. The most important step in this synthesis is the condensation of I‐methyltryptophyl bromide (4) with 2‐piperidone (5) to give N ‐(2‐(1‐methylidol)‐3‐ylethyl)‐2‐piperidone (6) in good yield (70%). The synthesis of 1‐benzoyl‐1, 2, 3, 4, 6, 7, 12, 12b‐octahydroindolo(2, 3‐a]quinolizine (2) and 1‐phenylcarbinol‐1, 2, 3, 4, 6, 7, 12, 12b‐octahydroindolo[2, 3‐a]quinolizine (3) follow the method developed by Wenkert. But the yield of tetrahydropyridine 9 from partial hydrogenation of pyridinum bromide 8 with 10% palladium‐charcoal is 84% which is much higher than the best yield (40%) in the literature, since the phenyl group contribute additional stability. Copyright © 1979 The Chemical Society Located in Taipei & Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim, Germany