T//-Carvone

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],... 

Batiu, I. Jimenez Esteller, L. Vapor-liquid equilibria in the binary system (-t)-carvone + (-r)-limonene at temperatures between 365 and 411 K ELDATA Int. Electron. J. Phys.-Chem. Data 1996,2, 59-66... 

Metabolic pattern of (-r)-carvone (93) is similar to that of (-)-carvone (93 ) in S. bottropensis. (-r)-Carvone (93) was converted by S. bottropensis to give (-r)-carvone-8,9-epoxide (96) and (+)-5a-hydroxycarvone (98a) (Figure 19.112). (-t)-Carvone-8,9-epoxide (96) has light sweet aroma and has strong inhibitory activity for the germination of lettuce seeds (Noma and Nishimura, 1982). 

FIGURE 19.129 Proposed metabolic pathways of (-t)-carvone (93) and (-)-isodihydrocarvone (101b) by Pseudomonas fragi IFO 3458. (Modi ed from Noma, Y. et al., Agric. Biol. Chem., 39, 437, 1975.)... 

The main renewable resource for L-carvone is spearmint oil (Mentha spicata), which contains up to 75% of this flavour chemical. There also exists a synthetic process for the manufacturing of L-carvone, which is based on (-t)-limonene, which is available as a by-product of the citrus juice industry as a major component of orange peel oil (Scheme 13.4). The synthesis was developed in the nineteenth century and starts with the reaction of (-t)-limonene and nitrosyl chloride, which ensures the asymmetry of the ring. Treatment with base of the nitrosyl chloride adduct results in elimination of hydrogen chloride and rearrangement of the nitrosyl function to an oxime. Acid treatment of the oxime finally results in l-carvone. 

Ce4+ is easily exchanged on resins such as Nation. Ce-Nafion catalyzed the oxidation of carveol to carvone with t-BuOOH as the oxidant no data characterizing leaching were provided (59). CeC>2 on AI2O3 was used as a solid catalyst for the cooxidation of cyclohexane and cyclohexanone. Products are dibasic acids and e-caprolactone. It was claimed that in water-free reaction conditions, Ce is not eluted from the solid (342). 

The two ketones are all flavour compounds too. The first, (-)-carvone, is the chief component (70%) of spearmintoil. Carvone is an interesting compound in Chapter 16 you will meet mirror-image isomers known as enantiomers, and (-)-carvone s mirror image (+)-carvone, is the chief component (35%) of dill oil. Our taste can tell the difference, though an NMR machine can t and both carvones have identical NMR spectra. See Chapter 16 for more detailf The second ketone is raspberry ketone and is largely responsible for the flavour of... 

Miyashita M, Suzuki T, Yoshikoshi (1985) Highly Efficient Conversion of (—)-Carvone to (+)-56-Hydroxycarvone. J Org Chem 50 3377... 

Maruoka has successfully developed a highly accelerated Oppenauer oxidation [31,32] system using a bidentate aluminum catalyst [29]. This modified, catalytic system effectively oxidizes a variety of secondary alcohols to the corresponding ketones as shown in Sch. 9. For example, reaction of (2,7-dimethyl-l,8-biphenylene-dioxy)bis(dimethylaluminum) (8, 5 moI%) with carveol (14) at room temperature in the presence of 4-A molecular sieves, and subsequent treatment with pivalaldehyde (3 equiv.) at room temperature for 5 h yielded carvone (15) in 91 % yield. Under these oxidation conditions, cholesterol (16) was converted to 4-cholesten-3-one (17) in 75 % yield (91 % yield with 5 equiv. t-BuCHO). 

Worm M, Jeep S, Sterry W, Zuberbier T. Perioral contact dermatitis caused by L-carvone in toothpaste. Contact Dermatitis 1998 38(6) 338. 

In order to determine the structure of the photochemical rearrangement product of carvone camphor in methanol, and to prove its structure, the research team of T. Gibson subjected the bicyclic carboxylic acid product to a degradation sequence, which commenced with the HVZ reaction, followed by dehydrohalogenation, dihydroxylation and glycol cleavage. 

The tricyclic ring system containing the fully functionalized CD ring of taxol was prepared from (S)-(+)-carvone by T.K.M. Shing et al. The bicyclic a-hydroxy ketone (4-hydroxy-5-one) was isomerized by an Intramolecular redox reaction in the presence of catalytic amounts of aluminum isopropoxide. This example was a special case where both reactants were in the same molecule the ketone was the oxidant for the Oppenauer oxidation, whereas the secondary alcohol was the hydride donor for the MVP reduction. The conversion to the thermodynamically more stable 5-hydroxy-4-one proceeded in good yield. 

Shing, T. K. M., Lee, C. M., Lo, H. Y. Synthesis of the CD ring in taxol from (S)-(+)-carvone. Tetrahedron Lett. 2001,42, 8361-8363. Marchand, A. P., Kumar, V. S., Hariprakasha, H. K. Synthesis of novel cage oxaheterocycles. J. Org. Chem. 2001,66, 2072-2077. Demnitz, F. W. J., Philippini, C., Raphael, R. A. Unexpected Rearrangement in the Peroxytrifluoroacetic Acid-Mediated Baeyer-Villiger Oxidation of trans-3p-Hydroxy-4,4,10p-trimethyl-9-decalone Forming a 7-Oxabicyclo[2.2.1]heptane. Structure Proof and Total Synthesis of ( )-Farnesiferol-C. J. Org. Chem. 1995, 60, 5114-5120. 

Baysal, T. and Starmans, D.A.J. (1999). Supercritical carbon dioxide extraction of carvone and limonene from caraway seed. Journal of Supercritical Fluids, 14 225-234. 

Both enantiomeric forms of carvone are readily available. /-(-)-Carvone (20) is the major constituent of spearmint oil from Mentha spicata, whereas 6/-(+)-car-vone is a major constituent of caraway oil from the fruit of Carum cami or dill from the fruit of Anethum graveolens. t/Z-Carvone is found in gingergrass oils. 

In another study, Rhodococcus globerulus PWD8 was found to oxidize D-limonene regio- and enantioselectively via (-t-)-trans-carveol to (+)-carvone [192l... 

Limonene is a liquid with lemon-like odor. It is a reactive compound oxidation often yields more than one product. Dehydrogenation leads to p-cymene. Limonene can be converted into cyclic terpene alcohols by hydrohalogenation, followed by hydrolysis. Nitrosyl chloride adds selectively to the endocyclic double bond this reaction is utilized in the manufacture of (-)-carvone from (-t-)-limonene (see p. 64). 

Total annual production is about 1200 t, 30-50% being of the native type and 50-70% of the Scotch type [637b], Other cultivation areas for spearmint oils exist in China and India (together ca. 1000 t), where oils are produced with very similar compositions to the US oils. Oils with a higher carvone content are obtained by redistillation [634b-634d],... 

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