Abstract A two-step synthesis of various enantiomerically pure 1-aryl-3-methylisochroman derivatives was accomplished through asymmetric biocatalytic ketone reduction followed by an oxa-Pictet–Spengler reaction. The compounds were obtained in good to excellent yield (47–92%) in favor of the syn diastereomers [dr (syn/anti) up to 99: 1]. Enantiopure arylpropanols serving as pronucleophiles for the C–C bond-formation step were obtained ...