S Carvone

The difference m odor between (R) and (S) carvone results from their different behavior toward receptor sites m the nose It is believed that volatile molecules occupy only those odor receptors that have the proper shape to accommodate them Because the receptor sites are themselves chiral one enantiomer may fit one kind of receptor while the other enantiomer fits a different kind An analogy that can be drawn is to hands and gloves Your left hand and your right hand are enantiomers You can place your left hand into a left glove but not into a right one The receptor (the glove) can accommodate one enantiomer of a chiral object (your hand) but not the other... 

Bioassay of alternate molecular forms supports the view that the ORs are capable of resolving isomeric distinctions in neutral (non-biological) odourants. Stereochemical pairs of odours were tested for differential sensitivities in the blind subterranean mole rat (Spalax ehrenbergi). The subjects responded to one enantiomer, but not to its stereoisomer. Both sexes were attracted to the odour of R-(-)-carvone but unresponsive to S-(+)-carvone in contrast, males and females were repelled by the odour of (+)-citronellol, but not by (-)-citronellol (Heth et al., 1992). The lack of responsiveness by mole rats could be central due to lack of salience, or peripheral due to hyposmia/anosmia for one isomer. Both carvones have distinct odours for the human nose. 

Carvone S-carvone is responsible for the odor of spearmint ( WSliRr), and the... 

A total synthesis of functionalized 8,14-seco steroids with five- and six-membered D rings has been developed (467). The synthesis is based on the transformation of (S)-carvone into a steroidal AB ring moiety with a side chain at C(9), which allows the creation of a nitrile oxide at this position. The nitrile oxides are coupled with cyclic enones or enol derivatives of 1,3-diketones, and reductive cleavage of the obtained cycloadducts give the desired products. The formation of a twelve-membered ring compound has been reported in the cycloaddition of one of the nitrile oxides with cyclopentenone and as the result of an intramolecular ene reaction, followed by retro-aldol reaction. 

Jenniskens LHD, Groot A, Enantioselective synthesis of R-(-)-Ligularenolide and the progesterone receptor figand R-(-)- PF1092C starting from S-(+)-carvone, Tetrahedron 54 5617—5622, 1998. 

It was also reported that there were slight differences in the activity of enantiomers. (R)-(-i-)-Limonene and (iI)-(-t)-carvone were more biologically active than their isomers (S)-(-)-limonene and (S)-(-)-carvone [115],... 

FIGURE 1-23 Stereoisomers distinguishable by smell and taste in humans, (a) Two stereoisomers of carvone R) carvone (isolated from spearmint oil) has the characteristic fragrance of spearmint (S)-carvone (from caraway seed oil) smells like caraway, (b) Aspartame, the artificial sweetener sold under the trade name NutraSweet, is easily distinguishable by taste receptors from its bitter-tasting stereoisomer, although the two differ only in the configuration at one of the two chiral carbon atoms. 

Carvone (94) occurs as (+)-carvone, (-)-carvone or racemic carvone. (S)-(+)-Carvone is the main component of caraway oil (ca 60%) and dill oil and has a herbaceous odour reminiscent of caraway and dill seeds. (R)-(-)-Carvone occurs in spearmint oil at a concentration of 70-80% and has a herbaceous odour similar to spearmint [26]. (S)-(+)-Carvone (94) was used as substrate for bioconversions by selected microorganisms five... 

Carvone is known to inhibit fungal growth of Fusarium sulphureum when the substrate was administered via the gas phase [73]. Under the same conditions, the related fungus, F. solani var. coeruleum was not inhibited. In liquid medium, both fungi were found to convert (S)-(+)-carvone with the same rate, mainly to isodihydrocarvone, isodihydrocarveol and neo-isodihydrocarveol. 

Ionene, a commercial fragrance, has been prepared traditionally by treatment of a- and /3-iononcs with hydriodic acid containing phosphorus or by distillative heating in the presence of 0.5% iodine. In an unoptimized demonstration, cyclization occurred more cleanly and simply by MBR with /3-ionone in water at 250 °C (Scheme 19) [83]. Work-up also was facilitated, as the need for removal of catalyst or the formation and separation of bi-products was avoided. At elevated temperature, the addition of water to olefins can occur readily, without adding catalyst. (S)-(+)-carvone in water for 10 min at 180 °C afforded optically pure 8-hydroxy-p-6-mcnlhcn-2-one as an intermediate toward carvacrol [84], Addition of water across the 8,9-double bond of carvone occurred regioselectively, by Markovnikov addition. Carvacrol itself was obtained almost quantitatively from carvone at 250 °C after 10 min (Scheme 19) [84]. 

Finally, this chemistry was employed to access welwitindolinone A. This required the preparation of (-)-fischerindole I, which was achieved using the same route previously described starting from (S)-carvone. This starting... 

Scheme 31 Initial synthesis of welwitindolinone A isonitrile from (S)-carvone oxide by Baran...

Which of the following properties or methods can be used to distinguish between (R)-carvone and (S)-carvone ... 

R)-Carvone and (S)-carvone are enantiomers and can be distinguished from each other by their optical rotations, by circular dichroism and by smell. Laevorotatory (R)-carvone has a spearmint smell (spearmint = Mentha spicata), whilst (S)-(+)-carvone has a caraway odor. 

S )-Carvone Anethum graveolens dill seed oil), Carum OD-R (caraway) [antiseptic,... 

Oosterhaven, K., Hartmans, K.J. and Huizing, H.J. (1993) Inhibition of potato Solanum tuberosum) sprout growth by the monoterpene S-carvone reduction of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity without effect on its mRNA level. /. Plant Physiol., 14,1463-9. 

Prins-pinacol condensation of a (Z)-a,p-unsaturated aldehdye and an (S)-carvone-derived alkynyl dienyl diol as illustrated below provided the formyl tetrahydroisobenzofuran as a single diastereomer in 84% yield in two steps <03JA6650>. 

SYNS (+)-CARVONE d(+)-CARVONE (S)-CARVONE (S)-(+)-CARVONE FEMA No. 2249 d-p-MENTHA-6,8,(9)-DIEN-2-ONE d-l-METHYL-4-ISOPROPENYL-6-CYCLOHEXEN-2-ONE (S)-2-METHYL-5-(1-METHYLETHENYL)-2-CYCL0HEXEN-1-ONE... 

S)-(+)-Carvone (17) has itself served as the starting material in the synthesis of the tricyclic lactone, eucannabinolide (18)(ref.17) and in that of the wheat plant fungal toxin helminthospoal (19) (ref.18). By contrast,(R)-(-)-carvone has been engaged as the intermediate for the formation of the epoxydilactone, picrotoxinin (20) (ref.19). 

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