Routes based on a 1-indanone types of intermediates are not as simple as direct reduction of an imine or oxime. It is reported that the wrong diastereomers are formed (cis) whereas the trans isomers are the ones that are needed. This frustrates the synthesis since an extra step has to be inserted. First the ketones are reduced to get mostly cis alcohols, which are then converted to the corresponding mesylates conserving stereochemistry. These can then be reacted with e.g. N-methylbenzylamine, effecting a Walden inversion (SN2). Final removal of the benzyl affords product, although it is racemic.