The invention relates to a process for preparing enantiomerically pure alcohol of the formula 1, which comprises (i) reducing the ketone of the formula 3to the racemic alcohol of the formula 4, (ii) enantioselectively acylating the racemic alcohol of the formula 4 with succinic anhydride in the presence of a lipase to give the succinic semiester of the formula 7, (iii) separating off the succinic semiester of the formula 7 from the unreacted enantiomer of the formula 4, (iv) reacting the enantiomerically pure alcohol of the formula 4 with methylamine to give the enantiomerically pure alcohol of the formula 1.