P-Mentha-l,8-diene

Synonym d-p-mentha-l,8,-diene, (R)-(+)-p-mentha-l,8-diene, (+)-l-methyl-4-(l-methylethenyl)cyclohexene, p-mentha-1,8-diene, carvene, cinene, citrene, cajeputene, kautschin Chemical Name dextro-limonene, (R)-(+)-limonene CAS Registry No 5989-27-5 Molecular Formula C10H16 Molecular Weight 136.234 Melting Point (°C) ... 

SYNS CYCLOHEX-l-ENE-l-METHANOL, 4-(l -METH-YLETHENYL)- DIHYDROCUMINYL ALCOHOL 4-ISOPROPENYL-CYCLOHEX-l-ENE-l-METHANOL p-MENTHA-l,8-DIEN-7-OL PERILLOL PERJLLYL ALCOHOL... 

R)-(+)-p-Mentha-l,8-diene see (R)-(+)-4-Isopropenyl-1 -methylcyclohex-1 -ene p-Mentha-6,8-dien-2-one see (S)-(+)-4-Isopropenyl- l-methylcyclohexen-6-one (-)-p-Mentha-6,8-dien-2-one see (R)-(-)-4-Isopropenyl-l-methylcyclohexen-6-one (lS,4R)-p-Menthan-3-one see (2S, 5R)-2-Isopropyl-5-methylcyclohexanone (-)-Menthone see (2S,5R)-2-Isopropyl-5-methylcyclohexanone Mesitylene see 1,3,5-Tiimethylbenzene Metaformaldehyde see 1,3,5-Tiioxane... 

Mattison et al. (1971) isolated Penicillium sp. cultures from rotting orange rind that utilized limonene (68) and converted it rapidly to a-terpineol (34). Bowen (1975) isolated two common Citrus moulds, Penicillium italicum and Penicillium digitatum, responsible for the postharvest diseases of Citrus fruits. Fermentation of Penicillium italicum on limonene (68) yielded cis- (81b) and /rani -carveol (81a) (26%) as the main products, together with cis- and /ra 5 -p-mentha-2,8-dien-l-ol (73) (18%), (+)-carvone (93 ) (6%), p-mentha-l,8-dien-4-ol (80) (4%), perillyl alcohol (74) (3%), and 8-p-menthene-l,2-diol (71) (3%). Conversion of 68 by Penicillium digitatum yielded the same products in lower yields (Figure 14.29). 

Polyester, PBT 3-9 d-p-Mentha-l,8-diene Fluorinated Ethylene Propylene Copolymer ... 

S) -(-)-p-Mentha-1,8-diene (S)-p-Mentha-l, 8-diene. See l-Limonene ( )-1,8-p-Menthadiene. See dl-Limonene p-Menth-1,4(8)-diene. See Terpinolene... 

Both the (+)- and (-)- enantiomers of limonene were transformed by larvae of the cutworm Spodop-tera litura (Miyazawa et al. 1998). For both of them the reactions involved are (a) dihydroxylation between C-8 and C-9 and (b) oxidation of the C-1 methyl group to carboxyl. These transformations were not dependent on the intestinal microflora in contrast to the transformation of a-terpinene to p-mentha-l,3-dien-7-ol and p-cymene whose formation could be attributed to the intestinal flora. 

Recently the most employed method for the production of A9-THC on industrial scale is the condensation of (+)-p-mentha-2,8-dien-l-ol (5.1 in... 

Selenium dioxide is also an oxygen donor to alkenes. In this case, however, the initial reaction of the double bond is with the selenium center followed by two pericyclic steps. After hydrolysis of the organo-selenium intermediate, the result is a hydroxylation at the allylic carbon position65. Thus, limonene (2) yields racemic p-mentha-l,8(9)-dien-4-ol66. The high toxicity of selenium intermediates and prevalence of many rearrangements has limited the widespread use of the reagent in synthesis. 

KOBu -DMF is the preferred reagent in tosylate elimination reactions with no accompanying substitution reactions [(—)-menthyl tosylate, (—)-bornyl tosylate, (-t-)-carvomenthyl tosylate] the tosylate of (-l-)-dihydrocarveol (164) gives a good yield (85%) of (-)-p-mentha-3,8-diene and (—)-p-mentha-2,4(8)-diene as sole products, presumably via base-catalysed rearrangement of isolimonene. ... 

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

SYNS FENL-t No. 2633 (-H)-4-ISOPROPENYL-l-METHYLCYCLOHEXENE d-(-l-)-LIMONENE (-l-)-R-LLMONENE d-p-MENTHA-1,8-DIENE j MENTHA-1,8-DIENE D (R)-l-METHYL-4-(l-METHYLETHENYL). CYCLOHEXENE NCI-C55572... 

A mixture of 2.88 g (16.0 mmol) of olivetol, 2.45 g (16.1 mmol) of (+)-cis/trans-p-mentha-2,8-dien-l-ol, and 2 g of anhydrous magnesium sulfate was stirred with 100 mL of methylene chloride under N2 atmosphere. After cooling in an ice bath, 1 mL (8.1 mmol) of freshly distilled boron triffuoride etherate was added. The mixture was stirred for 1.5 hr at 0° C and 5 g of anhydrous sodium bicarbonate was added. The stirring was continued until the color had faded, at which time the reaction mixture was filtered and evaporated to give a colorless gum (5 g). On the basis of gas-liquid chromatography, it contained 50 percent... 

A mixture of 153 mg (0.85 mmol) of olivetol, 132 mg (0.87 mmol) of (-i-)-cjs//rans-p-mentha-2,8-dien-l-ol and 200 mg of anhydrous magnesium sulfate in 5 mL of methylene chloride was stirred and cooled to ice bath temperature. Fifty microliters of anhydrous stannic chloride (0.111 g, 0.4 mmol) was added and stirring and cooling was continued. After 10 minutes, the reaction mixture was analyzed by gas-liquid chromatography and shown to contain 30 percent of (-)-6a,10a- rans-l-hydroxy-3-n-pentyl-6,6,9-trimethyl-6a,7,8,10a-tetrahydrodibenzo[b,d]pyran. After quenching the reaction with sodium carbonate, the desired compound can be isolated from the reaction mixture. 

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