The Ten Proaporphine-Tryptamine Dimers

Turkish Roemeria hybrida produces ten proaporphine-tryptamine dimers, two of which, (–)-roehybridine [1] and (–)-roemeridine [8], were previously known. The dimers have been divided into three subgroups based on the stereochemistry at C-9 and at the spiro C-10 center. The first subgroup, syn 9-OMe axial, includes (–)-roehybridine [1], (–)-nor-roehybridine [2], (–)-O-methylroehybridine [3], (–)-roehybridine ß-N-oxide [4], and (–)-roehybramine [5]. The second subgroup, syn 9-OMe equatorial, has only two members, (+)-roehymine [6] and (+)-roebramine [7]. The third subgroup, anti 9-OMe axial, includes (–)-roemeridine [8], (–)-O-methylroemeridine [9], and (–)-roemebramine [10]. In the syn series, A, the proaporphine nitrogen atom and the non-basic nitrogen of the indole moiety are on the same side of ring D, whereas they are on opposite sides in the anti series, B. © 1990, American Chemical Society. All rights reserved.