Octen-3-ol

Because this molecule has a chiral carbon, with four different groups attached, it can exist as two optical isomers, denoted R and S. One smells of mushrooms, and the other smells rather mouldy. (The oct in its name means it has eight carbons in the chain, the number 1 refers to the double bond being between the first and second carbons in the chain, and the 3-ol tells you that the -OH group is attached to the third carbon.) 

Although the molecules have the same atoms joined up in the same sequence, the atoms are oriented differently in space, so they plug into and activate a different combination of olfactory receptors in the nose. (i )-(-)-l-Octen-3-ol is the main component of mushroom flavor, and is indeed known as mushroom alcohol - mushrooms only make this isomer. It is largely synthesized in the cap and gills of the mushroom. 

Linoleic acid is a dominant fatty acid in mushrooms (see p287). Enzymes in the mushroom break it down and l-octen-3-ol is one 

A future commercial source could be a member of the mint family, Melittis melissophyllum. The plant itself contains little of the compound, but on hydrodistillation of the flowering aerial parts, the essential oil obtained was found to contain a large amount (43-54%) of l-octen-3-ol. 

apart from mushrooms (and truffles), it crops up in many 

---

A highly diastereoselective alkcnylation of c/s-4-cyclopentene-l,3>diols has been achieved with 0-protected (Z)-l-iodo-l-octen-3-ols and palladium catalyst (S. Torii, 1989). The ( )-isomers yielded 1 1 mixtures of diastcrcomcric products. The (Z)-alkenylpalladium intermediate is thought to undergo sy/i-addition to the less crowded face of the prochiral cyclopentene followed by syn-elimination of a hydropalladium intermediate. 

Other food lures which have had practical use ia trapping insect pests include isoamyl saUcylate [87-20-7] for moths of the tomato and tobacco homworms, Manduca spp. heptyl butyrate [5870-93-0] for stinging yeUowjackets, Vespula spp. and l-octene-3-ol [3391-86-4] for the bloodsucking tsetse dies, Glossina spp. 

Acetoxyoctadienes 47 and 48 are suitable starting materials for the synthesis of l-octen-3-ol (Matsutake alcohol) (129), a fragment component of a Japanese mushroom. The synthesis has been accomplished by two methods. In one method, the terminal double bond of 47 was hydro-... 

In addition to the cucujolides, (R)-l-octen-3-ol 156 has been described as a pheromone compound in 0. mercator and 0. surinamensis [295]. The alcohol is produced by both sexes at low population densities, and during a later stage of adulthood. It is reported to be attractive at low concentrations (supporting the attractivity of the cucujolies) but strongly repellent at high dosages. The... 

Disubstituted dihydrofurans and dihydropyrans were prepared via allylic etherification [68] in a similar manner to dihydropyrroles (cf Section 9.4.6). Thus, diaste-reoisomeric ethers were generated by the reaction of cinnamyl tert-butyl carbonate with the copper alkoxide prepared from (Rj-l-octen-3-ol, depending on which enantiomer of the phosphoramidite ligand was used (Scheme 9.39). Good yields and excellent selectivities were obtained. RCM in a standard manner gave cis- and trans-dihydrofuran derivatives in good yield, and the same method was used for the preparation of dihydropyrans. 

A recent study in Ethiopia found the most effective attractant for tsetse flies was acetone, octenol, and cow urine (Belete etal, 2004). An American company markets Mosquito Magnet, a device that purportedly attracts mosquitoes with l-octen-3-ol, heat, carbon dioxide, and water vapor (Enserink, 2002). Simpler traps are being used in East Africa. A black-and-blue cloth, impregnated with insecticide, attracts mosquitoes with acetone and octenol, or alternatively, buffalo urine (Enserink, 2002). 

Hall, D. R., Beevor, P. S., Cork, A., Nesbitt, B. F., and Vale, G. A. (1984). l-Octen-3-ol. A potent olfectory stimulant and attractant for tsetse isolated from cattle odors. Insect Science and its Application 5,335-339. 

Vale, G. A. and Hall, D. R. (1985). The role of l-octen-3-ol, acetone and carbon dioxide in the attraction of tsetse flies Glossina spp. (Diptera Glossinidae) to ox odour. Bulletin... 

Table III shows that l-octen-3-ol and 2-heptenal were only detected in soya containing bread and that the latter has significant larger peak areas of 1-pentanol, 1-hexanol, l-penten-3-ol, hexanal and 2- heptanone compared to the control (p < 0.05). These differences could be caused either by addition of volatile compounds present in soya flour or by its lipoxygenase activity. The main volatile compound found in soya flour was limonene (75), of which the peak areas were similar in the soya flour containing bread and its control sample. Moreover minor volatile compounds of soya flour, like 1-pentanol, 1-hexanol and hexanal, increased steadily in soya samples, as can be seen in Table...

Uq 1.4378, may occur in the optically active form. It is found, for example, in lavender oil and is a steam-volatile component of mushrooms. l-Octen-3-ol is a liquid with an intense mushroom, forest-earthy odor that can be prepared by a Grignard reaction from vinylmagnesium bromide and hexanal. It is used in lavender compositions and in mushroom aromas. 

Unsaturated fatty acids also seem to undergo oxidative breakdown during cooking. The volatile compounds found in cooked products are generally the same as in the raw product. Frequently there are, however, quantitative differences between the cooked and the raw product. Flowever, not much is known about the thermal fatty acid breakdown, but possibly it involves decomposition of already formed hydroperoxides in the raw product and/or oxidation of already formed volatile compounds. For example, l-octen-3-ol occurs in raw cut mushroom, whereas l-octen-3-one cannot be detected. On the other hand, l-octen-3-one is found in relatively large amounts in cooked mushroom [26]. 

Products of the LOX pathway or compounds formed by autoxidation of fatty acids (Scheme 7.2) are also important for leek aroma [31, 163]. Volatile compounds of the LOX pathway are not pronounced in the aroma profile of freshly cut leeks owing to a high content of thiosulfinates and thiopropanal-S-oxide [30]. In processed leeks that have been stored for a long time (frozen storage), however, these aliphatic aldehydes and alcohols have a greater impact on the aroma profile owing to volatilisation and transformations of sulfur compounds [31, 165]. The most important volatiles produced from fatty acids and perceived by GC-O of raw or cooked leeks are pentanal, hexanal, decanal and l-octen-3-ol (Table 7.5) [31, 35, 148, 163, 164]. 

Isomerization of allylbenzene and l-octene-3-ol catalysed by various metals (Rh, Ru, Ir) modified with tppts, tppms and the carboxylated phosphines, depicted in Table 3, 41 (n=2), 42 (n=0,l,2) and 43 as well as with 100 (Table... 

---