Cyclohexene, 1-phenyl

Stable cA-1-phenyl-1-cyclohexene 24 photodimeiizes via Diels Alder cycloaddition to trans adduct 25 (Equation 1.33) [66] and the photoexcitation of dihydrobenzofuran-fused cyclohexenone 26 in net furan gives the trans fused Diels-Alder adduct 27 (Equation 1.34) [67]. 

Shi s method gives good results for disubstituted /f-alkenes compared to the Jacobsen epoxidation previously described, which is more specific for disubstituted Z-alkenes. Concerning the epoxidation of trisubstituted alkenes, the epoxidation of 1-phenyl-1-cyclohexene could not be validated because of... 

The preparation described here is a slight modification of a route published by King and Sharpless via the osmium-catalyzed asymmetric dihydroxylation (AD) reaction of 1 -phenyl-1-cyclohexene. The major strengths of this process are that either enantiomer can be prepared in high optical purity (> 99.5% ee) v/ithout the need for chromatography. 

Some experimentation afforded improvements to the process. For example, in the case of the AD reaction, both the osmium and chiral concentrations could be reduced to a level of 0.05 mol % and 0.25 mol %, respectively, or one-fourth the levels in the commercial AD-mix formulation, without compromising the yield and enantiomeric excess of the etude product. The volume of liquid was also reduced to one-fourth of the quantities reported (1.5 L of water and 1 L tert-butyl alcohol per mole of substrate versus 5 L of water d 5 L of tert-butyl alcohol per mole of substrate). Under these conditions the reaction mixture is a slurry, but the potassium ferricyanide dissolves as it reacts. Reducing the catalyst concentration had the effect of doubling the reaction time from 1 day to 2 days. Interestingly, a study on the use of reduced amounts of osmium in the AD reaction of 1-phenyl-1-cyclohexene concluded that reducing the quantity of osmium by half (to 0.1 mol %), doubled the reaction time without affecting the yield, but that further reductions h osmium content made the reaction too sluggish to be useful. ... 

Methyl-6-(W,/V-dimethylamino)-frans-4-nitro-frans-5-phenyl-cyclohexene... 

The cyclic diolefin formed can then dehydrogenate as was discussed previously for this type of compound, and the hydrogen eliminated may be transferred to -methylstyrene, as was previously discussed for phenyl-cyclohexene, resulting in the formation of cumene. The diaryldiolefin shown in this mechanism was synthesized and successfully cyclized to p-terphenyl in the presence of sodium 55). 

Cook, C.E., Brine, D.R., Quin, G.D., Perez-Reyes, M., and DiGuiseppi, S.R., Phencyclidine and phenyl cyclohexene disposition after smoking phencyclidine, Clin. Pharmacol. Ther., 31, 635-641, 1982. 

Important emissions from new carpets with a styrene-butadiene rubber latex backing adhesive are styrene, 4-phenyl cyclohexene and 4-vinyl cyclohexene. These... 

An earlier off-odor problem that surfaced was the presence of 4-phenyl-cyclohexene in styrene-butadiene coated paper (Koszinowski et al. 1980). This compound was created by a Diels-Alder condensation reaction involving a molecule of styrene and butadiene and is differentiated by its odor from the isomeric 3 and 1-phenyl-cyclohex-ene compounds which cannot be formed by such a condensation reaction. The recognition threshold of this compound in the headspace over an aqueous solution lies around a concentration of 10 pg/kg (10 ppb). The typical odor of this compound at concentrations of 4-phenyl-cyclohexene in paper over 4 mg/kg (4 ppm) is easily identified. AGC determination in this concentration range is also possible without difficulty and its identification with MS using the relative molecular mass of 158 and one of the retro Diels-Alder decomposition product fragments at m/e = 104 (styrene) and mJe = 54 (butadiene) is definitely possible. 

Bulman Page and coworkers have optimized conditions for the use of their 5-amino-2,2-dimethyl-4-phenyl-l,3-dioxane derived imminium salt catalyst 66, and introduced two new analogues (Figure 26) for asymmetric epoxidation. 1-Phenyl cyclohexene and 1-phenyl 3,4-dihydronaphthalene are epoxidized in up to 89% ee <2007JOC4424, 2007T5386>. 

Finally, emerging data suggest that reactive indoor pollutants may interact with other pollutants and lead to new compounds. For example, Wechsler has shown that ozone, either from office machines or entrained from outdoors, may interact with 4-phenyl-cyclohexene and generate adlehydes. 

Einen interessanten Reaktionsverlauf nimmt die Formylierung von 3-Oxo-cyclohexenen. Bei der Einwirkung von Ameisensaure-ethylester auf 3-Oxo-l-phenyl-cyclohexen erhalt... 

Methyl-6-(f/,N-dimethylamino)-(rans-4-nitro-frafis-5-phenyl-cyclohexene... 

A number of other aryl-cyclic amine functionalities were examined as replacements for the 1,2,3,6-tetrahydro-4-phenylpiperidine of 36 (Table 6). Thiophene analogue 41 was found to have somewhat weaker DA D2 receptor affinity. In the 1,4-cyclohexenyl series 2-pyridylpiperazine attached to the phenyl cyclohexene produced potent compounds. The 1,5-cyclohexenyl analogue 42 having a 2-pyridylpiperazine group was also an interesting compound. However, the parent tetrahydropyridine 36 caused greater decreases in DA synthesis than piperazine 42. Replacement of the 2-pyridyl group with phenyl (43) or 2-pyrimidyl (44) resulted in compounds with decreased receptor affinity and in vivo activity. 

To a 50-mL round-bottomed flask equipped with a Friedrich condenser was placed 5.0 g methyl c/ s -2-phenylcyclohexylxanthate. A gas bubbler was attached to the condenser so that the course of the decomposition could be followed. The flask was immersed in a Wood s metal bath, and the temperature was gradually increased. A slight decomposition began when the bath temperature reached 165°C. It was then raised to 210-215°C, maintained at that level for 40 min, and then it was increased to 235-240°C for 5 min. After cooling, the material in the flask was transferred to a 10-mL modified Claisen flask and distilled. 3-Phenyl-cyclohexene in two fractions, with a combined weight of 2.1 g (71%), came over at70-71°C(2mmHg). 

The a-allylpalladium intermediate 135a, which must be formed on coupling of l,3-dicyclopropyl-l,2-propadiene (134), with, for example, iodobenzene under palladium catalysis rapidly undergoes rearrangement to the homoaUylpalladium species 135b and subsequent P-hydride elimination to yield the 1,3,5-hexatriene 136 [152g,h]. This in turn undergoes [4 + 2] cycloaddition with an added dienophile to furnish the 3-(2-cyclopropyl-l-phenyl)cyclohexene derivatives 138 as a mixture of trans,trans- and ds,trows-diastereomers (Scheme 8.31). 

Cyclohexen-l-yl isocyanide 1521, rac-4-fert-butyl-cyclohexen-l-yl isocyanide, and rac-4-phenyl-cyclohexen-l-yl isocyanide were likewise prepared by a similar method using gaseous phosgene to furnish the vinyl isocyanides in yields of 71-80% [1168], These were applied in a multicomponent approach to novel totally protected precursors of PNA monomers through an Ugi 4CR. 

Methyl-3-[4 nitro-phenyl]-cyclohexen-(6) on-(5)-carbQDB iire-(2) athyle8ter 10, 744. 

Non-stereospecific photochemical [2+2]-cycloadditions occur in the dimerization of phenyl cyclohexene 23 in the presence of a sensitizer to produce 24 and 25 [17], and in reactions of Z/E-2 butene with cyclohexenone 26 to give 27 and 28 [18] through the formation of intermediate diradicals. The photoaddition of cyclohexene to an enolised form of 1,3 diketone 29 gives 30 in a concerted process via the formation of an unstable cycloadduct [18]. 

Carboxylated styrene-butadiene dispersions have a solids content of about 52%, a pH between 7.5 and 9.0, and a monomodal particle size distribution with an average diameter of about 150 nm. With this small particle size, the instantaneous conversion during emulsion polymerisation is high, which leads to low concentrations of by-products, such as 4-phenyl-cyclohexene (4-PCH) and 4-vinyl-cyclohexene (4-VCH) generated by Diel-Alder reaction of styrene and butadiene. 4-PCH and 4-VCH concentrations are required to be below certain limits, since they have a very low odour threshold. 

Chloro-3-(2-phenyl-4E -l-benzopyran-4-yHdene)ethyHdene)-1-cyclohexen-l-yl)-2-phenyl-1-benzopyryHumperchlorate. 

Phenylthiazirine (40) can be isolated as an intermediate in the photolysis of 5-phenyl-1,2,3,4-thiatriazole and also from other five-membered ring heterocycles capable of losing stable fragments see Scheme 2 (81AHC(28)231). Photolysis of 5-phenylthiatriazole in the presence of cyclohexene yields cyclohexene episulfide (60CB2353) by trapping the sulfur atom. 

---