2-Methyl-(4’-tert-butyl)cinnamaldehyde (1) was reduced by Saccharamyces cerevisiae (baker’s yeast) to S-3-(4’-tert-butyl)-phenyl-2-propanol (4) in high chemical and very high optical yield (e.e. greater than or equal to 99%). Chlorination of 4 to 5, and alkylation of the corresponding cyclic amines complete this short enantioselective synthesis of S-1-(1’-pyperidino)-2-methyl-3-(4’tert-butyl)-phenyl-propane (6) and S-1-(1’-(3’,5’-cis-dimethyl)morpholino)-2-methyl-3-(4’-tert-butyl)-phenyl-propane (7), the S-enantiomers of fenpropidine and fenpropimorph, commercialy important systemic fungicides.