Studies on analogs of DAMASCENOLIDETM: Part 3. Synthesis and odor evaluation of dimethylated, cyclopropanated, and other analogs of DAMASCENOLIDETM.

DAMASCENOLIDETM [1, 4-(4-methylpent-3-en-1-yl)furan-2(5H)-one], which has a citrus-like odor, is an important aroma component of roses. We have previously reported on the synthesis and odor evaluation of 24 analogs of 1 as part of our new aroma compound developing project. To accumulate more information on structure-odor relationships, 10 more promising analogs such as dimethylated and cyclopropanated analogs were synthesized and subjected to odor evaluation. As a result, it was found that dimethylation of the furanone ring affected the odor. It was also found that cyclopropanation of 1 affected the odor, whereas cyclopropanation of the double bond isomer of 1 did not significantly affect the odor. The effects on the odor caused by ring size expansion and replacement of the side chain were also investigated.