Résumé : Reaction of 2‐methyl‐2‐benzyl‐1,2,3,4‐tetrahydroisoquinolinium iodide with sodium amide in liquid ammonia yields 76% 1‐orthotolyl‐2‐methyl‐1,2,3,4‐tetrahydroisoquinoline resulting from a Sommelet‐Hauser rearrangement. in the same conditions, 2,2‐dimethyl‐1,2,3,4‐tetrahydroisoquinolinium iodide yields 4% N,N‐dimethyl‐2‐vinylbenzylamine resulting from an elimination reaction and 70% 1‐(2‐dimethylaminomethy Iphenyl)‐2‐[2‐(β‐dimethylaminoethylphenyl)]‐cyclo‐propane, probably trans, (IX) resulting from dimerization followed by γ‐elimination. Copyright © 1969 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim