Revised Stereostructure for (+)-Roemecarine and Synthesis of (±)-, (+)-, and (-)-Roemercarine and (±)-Epiroemecarine

Abstract

The stereostructure of (+)-roemecarine, a new 1-benzyl-1, 2, 3, 4-tetrahydroisoquinoline having a hydroxyl group at the 4-position, was confirmed to be 1, 4-trans by synthesis of (±)-epiroemecarine (1) and (±)-roemecarine (5) via o-quinol acetates of isocodamine (4). Furthermore, (+)- and (-)-roemecarine (5) were synthesized in good chemical and optical yields by kinetic resolution of (±)-4-O-acetyl- (3) or (±)-4, 6-O, O-diacetylroemecarine (7) by the use of immobilized lipase OF-360 (Candida cylindracea) in organic solvents. (+)-Roemecarine (5) was proved to have 1S, 4S-configuration.