Resolution, EPC‐Syntheses, Absolute Stereochemistry, and Pharmacology of the (S)‐(+)‐ and (R)‐(—)‐Isomers of the MAO‐A Inhibitor Tetrindole Hydrochloride

Resolution of (RS)-tetrindole (3) and enantioselective reductions of the imine 7 yielded (S)-(+)-(4) and (R)-(−)-tetrindole (5). The absolute stereochemistry of 4 was established by X-ray analysis of the corresponding Mosher amide 6. From in vitro as well as in vivo data (MAO-inhibiton, levels of monoamines and their respective metabolites in rat brain), 4 was identified as the eutomer.