Asymmetric hydrogenation of dihydro-pyrido [1,2-a]indoles

A process for the asymmetric hydrogenation of 6,7-dihydropyrido[1,2-a]indole-8-methanol or its aromatically-substituted derivatives of the formula II wherein R1, R2 and R3 each, independently, is hydrogen, halogen, C1-7-alkyl, C1-7-haloalkyl, hydroxy, C1-7-alkoxy, C1-7-alkylthio, C1-7-alkylsulfinyl, C1-7-alkylsulfonyl, nitro, amino or acylamino, to (S)- or (R)-compounds of the formulanificances given above and the asterisk (*) denotes the chiral center, carried out using optically active rhodium-diphosphine complexes as catalysts, is described. The production of the compounds II, which also form an object of the invention, is also described. The compounds I and II are valuable intermediates, for example, for the preparation of pharmaceutically active substances.