Fluoride ion-induced desilylation of 1-methyl-1-(trimethylsilyl)methyl-2-(2-substituted phenyl)pyrrolidinium (3a), -piperidinium (3b and 3c), and -perhydroazepinium iodides (3d and 3e) gave high yields of eight- (5a), nine- (5b and 5c), and ten-membered cyclic amines (5d, 5e, 6d and 6e), containing conjugated-triene bond systems. These triene products are intermediates in the Sommelt-Hauser rearrangement of cyclic 1-methyl-2-phenylammonium 1-methylides (4), and were isomerized to the corresponding Sommelet-Hauser rearrangement products (7) in the presence of a strong base or an acid (except for 5b). Heating of these trienes in xylene yielded mixtures of the Stevens rearrangement products (8) and ring-opened amines (9). Selective formation of 8 was achieved by ultraviolet irradiation of the trienes (5) in hexane. The reaction mechanisms are discussed.