Asymmetric synthesis and sensory evaluation of sedanenolide.

The synthesis and sensory evaluation of enantiomeric sets of sedanenolide (1) and 3-butylphthalide (3) are described. The asymmetric synthesis was achieved via the intramolecular Diels-Alder reaction of chiral propargylester (5) which was prepared from optically active propargyl alcohol (4) and 2,4-pentadienoic acid. The sensory evaluation of these enantiomers revealed that there were distinct differences between their aroma character and odor threshold.