The synthesis and adrenergic activity of stereoisomeric 1-methylamino- and 1-isopropylamino-2-(3, 4, 5-trimethoxyphenyl)-5, 6-dihydroxy-1, 2, 3, 4-tetrahydronaphthalenes (IIa, b and IIIa, b), rigid structures related to the benzylamine derivatives (I), are presented. These compounds were found to possess direct β-stimulating activity both in the isolated tracheal and right atrial preparations of the guinea pigs. The structure-activity relationship in this series is described.
