Enantiopure (9-Anthryl)(2-piperidyl)- and (9-Anthryl)(2-pyridyl)methanols – Their Use as Chiral Modifiers for Heterogeneous Hydrogenation of Keto Esters over Pt/Al2O3

A route toward the synthesis of the erythro isomer of (9-anthryl)(2-piperidyl)methanol is presented as well as resolution and assignment of the structure (through NMR). The use of both the erythro and threo enantiopure isomers of this new amino alcohol, and its precursor [(9-anthryl)(2-pyridyl)methanol], as chiral modifiers for the Pt/Al2O3 hydrogenation of ethyl lactate showed that the erythro isomer is not necessarily the most efficient chiral modifier. This is probably because of the 9-anthryl group. The enantioselectivities that this compound provides are not, as one would expect, higher than those observed with the naphthyl group.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)