Syntheses of (+)- and (-)-dihydropinidine and (+)- and (-)-epidihydropinidine by using yeast reduction of methyl (2-oxocyclohexyl)acetate.

(+) and (-)-Dihydropinidine and (+)- and (-)-epidihydropinidine were synthesized from hydroxy esters 1 and 2 which had been prepared by yeast reduction of methyl (2-oxocyclohexyl)acetate. The enantiomeric excess at the C-1 positions of 1 and 2 were both determined as more than 99% ee.