Trans-Limonene oxide

Hills, H. G. (1989). Fragrance cycling in Stanhopea pulla (Orchidaceae, Stanhopeinae) and identification of trans-limonene oxide as a major fragrance component. Lindleyana 4 61-67. 

The GC was calibrated using a mixture of known quantities of d-limonene, d-limonene oxide (cis and trans), 2-octanone, and carvone. GC analyses were performed by injecting 1 pi samples with 1 40 split (column flow split flow), into a Hewlett-Packard 5840A GC equipped with a flame ionization detector. A fused silica capillary column 50m x 0.25 mm i.d., coated with OV-101 as a liquid phase was used. Column temperature was programmed from 50-250 C at 10 C/min, and helium was used as the carrier gas. 

GC-MS. The major compounds were found to be trans-linalool oxide and a-terpineol, whereas the dry black pepper oil contained a- and (3-pinenes, d-limonene and (3-caryo-phyllene as major components. When fresh pepper oil was isolated by distillation and analysed by GC and GC-MS, the compounds were found to be of a different nature to that of fresh pepper aromatic compounds (Menon, 2000). 

Japanese authors have made comprehensive investigations of the rearrangements of oxiranes in the presence of solid acids, bases, and salts.The model compounds employed were cyclohexene oxide and 1-methylcyclohexene oxide. The effects of the acidic and basic properties of the catalysts on the selectivity were interpreted on the basis of the products obtained. The main products are carbonyl compounds and allyl alcohol isomers. Rearrangements of limonene oxide over acids and bases were studied on five different types of Al203 similar research has been carried out on 2- and 3-carene oxides, cis- and trans-carvomenthene oxides and a-pinene oxide. ... 

In double stereodifferentiation, the inherent diastereofacial preferences of the chiral reactants may reinforce or oppose one another. Heating (/ )-(+)-limonene with bicyclic oxaziridine (+)-(2/ ,3S)-(105) for 2 days at 60 °C resulted in a 90% yield of a 55 45 cis/trans mixture of limonene oxides (106) (Equation (24)) <91JOC809>. The cis/trans selectivity improved to 93 7 when (S)-(—)-limonene was used. 

The products of peracid oxidation of limonene have also been re-examined. Wylde and Teulon have shown that the best method for making pure cis-or trans- limonene 1,2-epoxides, a mixture of which is obtained by direct peracid oxidation in chlorinated hydrocarbon solvents, is to treat this mixture with hydrogen chloride in ether, when the two diaxial chlorohydrins (122) and (123) are obtained with practically no equatorially substituted isomers. Of these two isomers only (122) forms a p-nitrobenzoate, allowing (123) to be distilled from the residue. Treatment of the nitrobenzoate of (122) with methanolic potassium hydroxide now leads to the c/s-epoxide (120) similar treatment of... 

We recently expanded the range of polymerizable alicyclic epoxides to include the renewable epoxide limonene oxide (LO) (30) and the related VCHO, as shown in Table II (entries 2 and 3, respectively). The polymerization of a cis/trans mixture of (/ )-LO is considerably slower, presumably owing to the trisubstituted epoxide ring and the preference for the polymerization of the trans isomer (30). Conversely, VCHO undergoes rapid polymerization, with an activity comparable to that of CHO. This result supports the claim that the low activity of LO is due to the methyl group on the epoxide, not the vinyl substituent. 

The alternating copolymerization of cis/fraws-limonene oxide and carbon dioxide can be achieved with p-diiminate zinc acetate complexes (Scheme 5). The balance between high catalyst activity and selectivity is optimal with catalyst complex 8 (see Scheme 5, right) at 25°C. Catalysts exhibits high selectivity for the trans diasteriomer (% trans in the copolymer is >98%). The biodegradable polycarbonates have MWs in the range of 4.0-10.8 kg/mol, which can be controlled by the [epoxide]/[Zn] ratio, CO2 pressure, and reaction time. They also have narrow... 

Figure 22 Direct distillation of beverages by means of the SAFE technique (30 m X 0.25 mm I.D. DB-WAX 0.25 (im df 60°C-3°C/min — 230°C). Key to components identified in soft drink 1, limonene 2, y-terpinene 3, a-terpinolene 4, nonanal 5, hnalool 6, fenchol 7, l-terpinen-4-ol 8, a-terpineol 9, cinnamaldehyde 10, myristicin. Key to components identified in grapefruit juice 1, limonene 2, cis-linalool oxide (f) 3, trans-linalool oxide (f) 4, P-caryophyllene 5, a-terpineol 6, trans-carveol 7, dihydronootka-tone 8, nootkatone.

Microalgae were used for oxidation and hydroxylation of organic compounds (Fig. 3). For example, hydroxylation of (5 )-limonene affords a mixture of cis and trans carveols. " By hydroxylation and oxidation using Chlorella, " ... 

Grosjean, D., E. L. Williams, II, E. Grosjean, J. M. Andino, and J. H. Seinfeld, Atmospheric Oxidation of Biogenic Hydrocarbons Reaction of Ozone with /J-Pinene, d-Limonene, and trans-Caryophyllene, Em iron. Sci. Techriol., 27, 2754-2758 (1993a). 

Extension of the above oxidation studies to alkenes such as limonene gave a complex mixture of products that resulted from all possible ene reactions to the trisubstituted double bond (Fig. 30) [165], However, use of NaY zeolite as the microreactor and in the presence of a small amount of pyridine, the photosensitized oxidation of the alkenes is regioselective, yielding only the cis and trans products that result from hydrogen abstraction from the least hindered allylic carbon center. These studies illustrated that a microreactor can provide unprecedented opportunities to conduct selective oxidation of olefins. 

Qccurance and Identification. An early report of cotton volatile composition by Minyard et al. (44) involved steam distillation of large quantities of leaves and flowers. Major compounds identified included the monoterpenes a-pinene, B-pinene, myrcene, trans-B-ocimene, and limonene ( 4). Several other monoterpene hydrocarbons were also present in low concentration. Since that report, many other terpenes have been identified in cotton essential oil steam distillates and solvent extracts. These compounds include cyclic hydrocarbons such as bisabolene, caryophyllene, copaene and humulene (45-47), the cyclic epoxide caryophyllene oxide (45), cyclic alcohols such as bisabolol, spathulenol, and the aromatic compound... 

---