Nouvelle methode de synthese de tetrahydro-2,3,4,5 benzo (b) 1H-azepines substituees en position -2

Treatment of tertiary alcohols and trisubstituted olefins of the tetrahydronaphthalene series with the HN₃H₂SO₄ reagent leads directly and with good yields to a new class of compounds: the 3,4-dihydro 5H benzo (b) azepins substituted on position -2. The latter, on reduction, give the corresponding 2,3,4,5-tetrahydro 1H benzo (b) azepins, most of them being unknown in the literature. This work shows the high regiospecificity of this ring expansion reaction which can be explained by electronic and steric effects.