(1S,4R)-(-)-fenchone - camphoraceous, strong, diffusive, sweet odor Odor Threshold = 350 ppb in water (Pelosi et al.) Odor Threshold = 440 ppb in water (Padrayuttawat et al.) = (1S,4R)-(-)-1,3,3-Trimethyl-bicyclo[2.2.1]heptan-2-one Laska et al. found no significant discrimination between the odor of the two enantiomers for humans. This may have been due to panel acuity, as a number of the other enantiomers studied have been discriminated by other groups. Conversly, squirrel monkeys could discriminate the enantiomers of fenchone. Similarly, Rubin & Katz have shown that Fenchone is discriminated in the rat olfactory bulb. Ref: P. Pelosi & A.M. Pisanelli, Chemical Senses, 6, 87-93 (1981); L.J. van Gemert, Compilations of odour threshold values in air and water, Boelens Aroma Chemical Information Service, Publisher (1999), p. B-117; PADRAYUTTAWAT, A., T. YOSHIZAWA, H. TAMURA & T. TOKUNAGA (1997), Optical isomers and odor thresholds of volatile constituents in Citrus sudachi, Food Sci. Technol. Int. Tokyo, 3, 402-408; Matthias Laska and Peter Teubner, Olfactory Discrimination Ability of Human Subjects for Ten Pairs of Enantiomers, Chem. Senses 24: 161-170, 1999; Matthias Laska, Anne Liesen, and Peter Teubner, Enantioselectivity of odor perception in squirrel monkeys and humans, Am J Physiol Regul Integr Comp Physiol., Vol. 277, Issue 4, R1098-R1103, October 1999; Benjamin D. Rubin & Lawrence C. Katz, Spatial coding of enantiomers in the rat olfactory bulb, Nature Neuroscience 4, 355 - 356 (2001)

(1R,4S)-(+)-fenchone - camphoraceous, strong, diffusive, sweet odor Odor Threshold = 510 ppb in water (Pelosi et al.) Odor Threshold = 240 ppb in water (Padrayuttawat et al.) = (1R,4S)-(+)- 1,3,3-Trimethyl-bicyclo[2.2.1]heptan-2-one Ref: P. Pelosi & A.M. Pisanelli, Chemical Senses, 6, 87-93 (1981); L.J. van Gemert, Compilations of odour threshold values in air and water, Boelens Aroma Chemical Information Service, Publisher (1999), p. B-117; PADRAYUTTAWAT, A., T. YOSHIZAWA, H. TAMURA & T. TOKUNAGA (1997), Optical isomers and odor thresholds of volatile constituents in Citrus sudachi, Food Sci. Technol. Int. Tokyo, 3, 402-408; Matthias Laska and Peter Teubner, Olfactory Discrimination Ability of Human Subjects for Ten Pairs of Enantiomers, Chem. Senses 24: 161-170, 1999; Matthias Laska, Anne Liesen, and Peter Teubner, Enantioselectivity of odor perception in squirrel monkeys and humans, Am J Physiol Regul Integr Comp Physiol., Vol. 277, Issue 4, R1098-R1103, October 1999

Ionones, Irones, Damascones & Structurally Related Odorants

Acyclics (Alcohols, Esters, Acids, Aldehydes)

Lactones

Sesquiterpenoid Related Odorants