A continuous micro-structured reactor equipped with a perforated (5 mu m) membrane is used for the investigation of the gas-liquid-solid asymmetric hydrogenation of ethylpyruvate, on a Pt-gamma-Al2O3 catalyst modified with chiral inductors under high hydrogen pressure (45 bar). Up to eight chiral inductors have been evaluated, the best enantioselectivity (63%) being obtained with cinchonidine. The very low reaction volume (100 mu 1) offers short operating time. Solvent effect, deactivation studies and the effect of modifier leaching are also reported. (c) 2007 Elsevier B.V. All rights reserved.