(29) HR ing," Heterocyclic Compounds", Vol. 3, RC Elderfield. Ed., Wiley, New York, NY 1952, Chapter 5, p 396.(30) GR Clemo and GR Romage, J. Chern. SOC., 49 (1931).(31) In the mass spectrum of indolizine, the molecular ion is also the base peak de 117; in addition there are strong peaks due to parent HCN (go), parent HPCN (89), and parent CZH~(64); see ref 4.(32)(a) EM Gaydou, G. Peiffer, and M. Etienne, Org. Mass. Spectrom., 9, 157 ( ...