Syntheses and odor properties of optically active dimethyl octenone and its analogs

The optically active isomers of dimethyl octenone, which is used in citrus accords, and its analogs, were synthesized from a common chiral intermediate prepared by the lipase-catalyzed desymmetrization of prochiral diol. The results of an olfactory evaluation of the prepared isomers are also reported.

Figure optionsDownload as PowerPoint slide

(R)-3,6-Dimethyl-5-hepten-2-oneC9H16OEe = 95%[α]D24 = −27.6 (c 0.5, CHCl3)Source of chirality: lipase catalyzed reactionAbsolute configuration: (R)

(R)-4,7-Dimethyl-6-octen-3-oneC10H18OEe = 95%[α]D24 = −37.4 (c 1.1, CHCl3)Source of chirality: lipase catalyzed reactionAbsolute configuration: (R)

(R)-5,8-Dimethyl-7-nonen-4-oneC11H20OEe = 95%[α]D24 = −36.1 (c 0.5, CHCl3)Source of chirality: lipase catalyzed reactionAbsolute configuration: (R)

(R)-6,9-Dimethyl-8-decen-5-oneC12H22OEe = 95%[α]D24 = −34.6 (c 0.5, CHCl3)Source of chirality: lipase catalyzed reactionAbsolute configuration: (R)

(R)-2,5-Dimethyl-2-undecen-6-oneC13H24OEe = 95%[α]D24 = −32.3 (c 0.5, CHCl3)Source of chirality: lipase catalyzed reactionAbsolute configuration: (R)