Studies on Tetrahydroisoquinolines. XXIII. Reactions of (±)-7-Acetoxy-7-methoxy-1-(3, 4-dimethoxy-or 3, 4-methylenedioxybenzyl)-2-methyl-6-oxo-Δ^{4a, 5, 8, 8a}-hexahydroisoquinoline (o-Quinol Acetate)

Abstract

(±)-4-Acetoxy-1-benzyl-6-hydroxy-7-methoxy-2-methyl-1, 2, 3, 4-tetrahydroisoquinolines (3) (R=Me) were proved to be formed by thermal isomerization of o-quinol acetates (2). Reaction of 2 with organic acids gave the (±)-1, 4-trans-and cis-4-acyloxy-1-benzyl derivatives [3 (R=Me, Et, n-C₅H₁₁, and tert-Bu)]. With hydrohalic acids, 2 afforded (±)-1-benzyl-5-halogeno-6-hydroxy-7-methoxy-2-methyl-1, 2, 3, 4-tetrahydroisoquinolines [6 (X=Cl, Br)]. Stereochemical aspects of the reactions are discussed.