Ethyl cyclohexenyl ether

A quantitative comparison of metals in the hydrogenation of vinyl ethers has been made, The extent of hydrogenolysis in hydrogenation of l-ethoxy-3-methylcyclohexene decreased in the order Pt Os > Rh Ir > Pd > Ru U24e)-, in the case of ethyl 4-methyl-1-cyclohexenyl ether, the order was Pt Ir > Rh > Os Ru Pd (124d). In ethanol, ketal formation is a... 

Diels-Alder reaction, of acrolein with B-butyl cyclohexenyl ether, n-butyl vinyl ether, and ethyl isopropenyl ether, 34, 30... 

Under comparable conditions the submitters found that the corresponding dihydropyran derivatives were similarly obtained by the condensation of acrolein with methyl vinyl ether in 80-81% yield, with ethyl vinyl ether (77-85% yield), with w-butyl vinyl ether (82% yield), with ethyl isopropenyl ether (50% yield), and with w-butyl cyclohexenyl ether (40% yield). Other <, /3-un-saturated carbonyl compounds that have thus been condensed with ethyl vinyl ether are crotonaldehyde (87% yield), meth-acrolein (40% yield), a-ethyh/3-n-propylacrolein (54% yield), cinnamaldehyde (60% yield), /3-furylacrolein (85% yield), methyl vinyl ketone (50% yield), benzalacetone (75% yield), and benzal-acetophenone (74% yield). 

Povarov has reported that the addition of ethyl- 1-cyclohexenyl ether to benzylideneaniline and a number of its derivatives in the presence of boron trifluoride etherate provides the adducts (171a-d). 171a can be converted into 6-phenyl-7,8,9,I0-tetrahydrophenanthri-dine either by treatment with /j-toluenesulfonic acid or oxidation with potassium permanganate.200... 

Dicyclopen tadiene, 32,41 36,33 37,65 Dicyclopropyl ketone, 38,19 Diels acid, 35, 38 Diels-Alder reaction, of acrolein with n-butyl cyclohexenyl ether, n-butyl vinyl ether, and ethyl iso-propenyl ether, 34, 30 of butadiene with maleic anhydride, 30, 93... 

Trifluoromethylated pyrones can also be prepared from acyl chlorides by reaction with pyridine and trifluoroacetic anhydride followed by capture of the intermediate trifluoroacyl ketene 8 with suitable reagents. Thus, addition of A -cyclohexenyl-morpholine to the intermediate from palmitoyl chloride gave pyrone 9 as the major product, accompanied by amide 10. Ethyl vinyl ether yielded pyrones 11a and 11b (through p-elimination of ethanol) [9] (Scheme 5). 

Another example is the hydrogenation of the homoallylic eompound 4-methyl-3-cyclohexenyl ethyl ether to a mixture of 4-methylcyclohexyl ethyl ether and methylcyclohexane. The extent of hydrogenolysis depends on both the isomerizing and the hydrogenolyzing tendencies of the catalysts. With unsupported metals in ethanol, the percent hydrogenolysis decreased in the order palladium (62.6%), rhodium (23 6%), platinum (7.1%), iridium (3.9%), ruthenium (3.0%) (S3). 

Ethyl 1-bromocyclohexanecarboxylate, when treated with magnesium in anhydrous ether-benzene with subsequent addition of cyclohexanone, yields ethyl l-(l-hydroxycyclohexyl)cyclo-hexanecarboxylate. Dehydration and saponification give rise to l-(l-cyclohexenyl)cyclohexanecarboxylic acid, which upon decarboxylation at 195° yields cyclohexylidenecyclohexane in 8% overall yield, m.p. 540.4 This olefin has also been prepared by the debromination of 1,1 -dibromobicyclohexyl with zinc in acetic acid. ... 

To a stirred slurry of 35 mg (0.87 mmol) of sodium hydride in 5 mL of THF under a nitrogen atmosphere at OX is added 225 mg (0.80 mmol) of ethyl [4-oxo-1-(2-propenyl)-2-cyclohexenyl]methylpropanedioatein 3 mL of THF. After the evolution of hydrogen ceases the cooling bath is removed and the mixture is stirred for 2.5 h at 25 °C. The mixture is poured into cold 0.1 N aq HCI and then extracted three times with 10 mL of CH2n2. The combined extracts are washed with aq NaHCO, and water. After drying and evaporation of the solvent the crude product is recrystallized yield 197 mg (87%) mp 83-84 C (diethyl ether). 

Preparation of 4-12-cvclohexenvloxv )-stvrene. A stirred mixture of 34.36g (0.096 mole) methyltriphenylphosphonium bromide and 10.75g (0.096 mole) potassium t-butoxide in 200ml dry THF is treated drop-wise with a solution of 16.16g (0.080 mole) of 4-(2-cyclohexenyl)-benzaldehyde in 30ml THF under inert atmosphere. Once the addition of aldehyde was completed, the mixture was stirred at room temperature for another 2 hours. Ether and water were then added to the reaction mixture until clearly separated phases were obtained with no solid residue. The organic layer was separated and washed three times with water, dried over magnesium sulfate and evaporated. The resulting semi-solid was triturated in 10% ethyl acetate-hexane mixture to remove most of the triphenylphosphine and the evaporated extract was purified by preparative HPLC using hexane as eluent. This afforded 9.35g (58%) of the pure monomer, which was fully characterized by H and C-NMR as well as mass spectrometry. 

Judging from the number of incorrect names that appear in the chemical literature, it s probably safe to say that relatively few practicing organic chemists are fully conversant with the rules of organic nomenclature. Simple hydrocarbons and monofunctional compounds present few difficulties because the basic rules for naming such compounds are logical and easy to understand. Problems, however, are often encountered with polyfunctional compounds. Whereas most chemists could correctly identify hydrocarbon 1 as 3-ethyl-2,5-dimethylheptane, rather few could correctly identify poly functional compound 2. Should we consider 2 as an ether As an ethyl ester As a ketone As an alkeae It is, of course, all four, but it has only one correct name ethyl 3-(4-methoxy-2-oxo-3-cyclohexenyl)propanoate. 

Ethyl 2-oxocyclohexanecarboxylate Ethyl chloroformate (7.2 g, 0.066 mole) is added to a well stirred solution of 4-(l-cyclohexenyl)morphoIine (20.0 g, 0.12 mole) in anhydrous benzene (100 ml) under nitrogen, and the mixture is boiled under reflux for 10 h, then cooled and filtered. The precipitate of enamine hydrochloride is washed with anhydrous ether. The united filtrates are treated with 10% aqueous hydrochloric acid (22 ml) and the mixture is stirred vigorously for 15-30 min. The layers are separated, the aqueous phase is extracted with benzene, the organic phases are united, and the solvent is distilled off under reduced pressure. Fractionation of the residue gives 62% (6.2 g) of the /S-oxo ester, b.p. 112-115°/ 10 mm. 

Methylcyclohexanone diethyl acetal heated with 0.1% anhydrous p-toluenesulfonic acid at 100-110° under ca. 100 mm pressure with distillation of the resulting ethanol 4-methyl-1-cyclohexenyl ethyl ether. Y 82%. F. e. s. U. Schmidt and P. Grafen, A. 656, 97 (1962). 

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