Synthesis of (R)-6,7-dihydro-5-HETE lactone and (S)-6,7-dihydro-5-HETE lactone by using novel yeast reduction as a key reaction

Novel yeast reduction which gave (1R,2S)-hydroxy ester 10 and (1S,5S)-lactone 11 from racemic ketoester 12 was discovered. After 10 and 11 were converted to lactone 15 and 17, enantiomeric excesses were determined as 99% and 95%, respectively. This novel yeast reduction was applied to synthetic study of metabolites of 5-oxo-ETE 1. (R)-6,7-Dihydro-5-HETE lactone 5 and (S)-6,7-dihydro-5-HETE lactone 6 were synthesized from 15 and 17, respectively.