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-inhibition, levels of monoamines and their respective metabolites in rat brain), 4 was identified as the eutomer.