Studies the synthesis of optically pure (S)- and (R)-vinylpiperidine 2 and (S)- and (R)-(hydroxyethyl)piperidine 3, which were key intermediates for the synthesis of aloperine, from yeast-reductive products. Conversion of (R)-2 alcohol 7 to a corresponding mesylate by using mesyl chloride and triethylamine; Enantiomeric excess of (S)-piperidine.