4- Ethyl-cis-2-hexene

C8H16 4-ethyl-cis-2-hexene 54616-49-8 386.15 33.007 1,2 15048 C8H16N203 N-butyl-(3-carboxy propyl)nitrosamine 38252-74-3 308.75 25.861 1,2... 

In the feed section, the mainly l--hexene reactant (98.60% 1-hexene, 0.95% cis-3 hexene, 0.25% trans-2 hexene and 0.15% cis-2 hexene, supplied by Ethyl corporation) is introduced from an Instrumentation Specialties Company (ISCO) model 314 metering pump into a flowing stream of liquefied COo. The l-hexene/C02 mixture is then fed to a high pressure positive displacement pump contained in the SCESS. In this pump, fluids can be pressurized up to 6,000 psig and total flow rate can be adjusted between 46 ml/hr and 460 ml/hr. Since feed to the pump must be in a liquid state, both the l-hexene/C02 mixture and the pump head are sufficiently cooled by circulating chilled water at 5 C. The system pressure is controlled by means of an adjustable back pressure regulator. 

Figure 15.12 GC-GC chromatogram of a natural cw-3-hexen-l-ol fraction. Peak identification is as follows 1, ethyl-2-methylbutyrate 2, trans-2-hexenal 3,1-hexanol 4, cis-3-hexen-l-ol 5, frmw-2-hexen-l-ol. Adapted from Journal of High Resolution Chromatography, 15, S. Nitz el al., Multidimensional gas chromatography-isotope ratio mass spectrometry, (MDGC-IRMS). Part A system description and technical requirements , pp. 387-391, 1992, with permission from Wiley-VCH.

Determine whether each of the following molecules can exist as cis-trans isomers (1) 1-pentene, (b) 3-ethyl-3-hexene, and (c) 3-methyl-2-pentene. 

Thus, the double bond in 1-hexene is monosubstituted and the double bond in 2-hexene or 3-hexene is disubstituted. The trans isomer is the more stable compound (more negative H ). Figure 3.35 shows the reason in the cis isomer there is a cis ethyl-ethyl eclipsing that is absent in the trans compound. In the trans isomer, both alkyl groups are eclipsed by hydrogen, and the destabilizing ethyl—ethyl repulsion is missing. 

DIMETHYLCYCLOHEXANE cis-1,2-DIMETHYLCYCLOHEXANE trans-1,2-DIMETHYLCYCLOHEXANE cis-1,3-DIMETHYLCYCLOHEXANE trans-1,3-DIMETHYLCYCLOHEXANE c i s-1,4-DIMETHYLCYCLOHEXANE trans-1,4-DIMETHYLCYCL0HEXANE ETHYLCYCLOHEXANE 2-ETHYL-1-HEXENE... 

Ozonolysis of Tetramethylene and cis-3,4-Dimethyl- 3 -hexene. A solution of tetramethylethylene (0.503 gram, 5.98 mmoles) and cis-3,4-dimethyl-3-hexene (0.692 gram, 6.17 mmoles) in 20 ml pentane was ozonized to 63% theoretical yield at —40°C. The product mixture was analyzed by GPC using an 8-ft 10% XF-1150 column at 85°C and a flow rate of 150 ml/minute. The mixture contained 25 mg acetone diperoxide, 36.7 mg l,l,4-trimethyl-4-ethyl-2,3,5,6-tetraoxacyclohexane, and 23.2 mg methyl ethyl ketone diperoxide as determined by GPC using an internal standard. Total yield of diperoxides was 14%. The diperoxides were identified by comparing mp, infrared, NMR, and GPC data with those of authentic samples. 

Ozonolysis of cis-3,4-Dimethyl-3 -hexene. A solution of cis-3,4-di-methyl-3-hexene (98% pure, Chemical Samples Co.) (1.12 grams, 10 mmoles) in 50 ml pentane was ozonized at — 62°C until the blue color of excess ozone was evident. A nitrogen stream was used to purge the solution of excess ozone. Pentane was then carefully distilled off at atmospheric pressure. A water aspirator (20 mm Hg) was then used to remove the ketone product. Treatment of this material with 10 ml of an 0.1 M solution of 2,4-dinitrophenylhydrazine gave 2.33 grams of crude 2,4-dinitrophenylhydrazone. The crude product was recrystallized and identified as the 2,4-dinitrophenylhydrazone of methyl ethyl ketone, mp 115-116°C. Yield of the ketone was 92% based on olefin used. 

By choosing olefins of comparable reactivity towards ozone this difficulty can be avoided. When approximately equimolar amounts of 7 and cis-3,4-dimethyl-3-hexene, 8, were ozonized together all three predicted diperoxides were obtained—i.e., acetone diperoxide, 9, the cross diperoxide, l,l,4-trimethyl-4-ethyl-2,3,5,6-tetraoxacyclohexane, 10, and methyl ethyl ketone diperoxide, 11. 

It was now important to examine the question of a possible stereochemical influence on diperoxide formation. We have approached this problem initially by ozonizing olefins of type 2. When either cis- or trans-3,4-dimethyl-3-hexene are ozonized, presumably a single stereoisomeric pair of diperoxides can be formed. In fact, this case is complicated by the possibility of two trans-diperoxide conformers being produced. The cis-diperoxide conformers are identical. Ozonolysis of cis-3,4-dimethyl-3-hexene, 8, for example, could give the diperoxides, cis-l,3-dimethyl-l,3-diethyl-2,3,5,6-tetraoxacyclohexane, 11a, and rans-l,3-dimethyl-l,3-di-ethyl-2,3,5,6-tetraoxacyclohexane, lib, with the latter capable of existing as conformers lib and lib with trans-diaxial methyl and trans-diaxial ethyl substituents, respectively. 

The reaction is even more complicated when cis-trans isomerism is involved. Whereas tra 5-2,2,5,5-tetramethyl-3-hexene gives trans-di-tert-butylethylene ozonide, the cis isomer gives a mixture of 70% of cis ozonide and 30% of trans ozonide [79]. The ratios of cis and trans isomers may vary over a wide range depending mainly on the bulkiness of the alkyl groups at the double bonds. Whereas both cis- and tram-2-butene yield cis and trans ozonides in the ratio 2 3, cw-ethyl-tert-butylethylene gives cis and trans ozonides in the ratio 2 1. With the trans alkene, the ratio is 3 7 [76],... 

The main volatiles in wines are the higher aliphatic alcohols, ethyl esters, and acetates formed from yeasts during fermentation. Acetates are very important flavors characterized by fruity notes, C4-Ci0 fatty acid ethyl esters manly confer fruity scents to the wine. Other wine aroma compounds are C6 alcohols, such as 1-hexanol and cis- and trans-3-hexen-l-ol, 2-phenylethanol, and 2-phenylethyl acetate. Contents of these compounds in wine are linked to the winemaking processes used fermentation temperature, yeast strain type, nitrogen level in must available for yeasts during fermentation, clarification of wine (Rapp and Versini, 1991). Much literature on the wine aroma compounds was reported in reviews by Schreier (1979) and Rapp (1988). 

Allyl caproate Benzyl cinnamate Citral trans-trans-2,4-Decadienal Ethyl maltol Menthol cis-Methyl jasmonate Pine (Pinus pumilio) needle oil fragrance, fougeres detergents Dihydroterpinyl acetate fragrance, fresh outdoor scents 3-Hexenal... 

The crystal and molecular structure of 2-(a-p-bromophenyl-P-nitro)-ethyl-5-methylcyclohexanone (6), a product from reaction of l-morpholino-3-methylcyclo-hexene with p-bromo-P-nitrostyrene, has been determined. Although a cis-configu-ration was anticipated on a mechanistic basis, the n.m.r. spectral analysis did not provide an unequivocal answer. X-Ray analysis indicated a chair cyclohexanone ring with the methyl group axial and the substituted ethyl group equatorial. 

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