L-Methyl-2-cyclohexen

Four different syntheses were reported for the enantiomers of l-methyl-2-cyclohexen-1 -ol, a component of the aggregation pheromone of Dendrocton us pseudotsugae [47-50]. 

The mechanism of the reaction is unknown. The stereospecificity observed with (E)- and (Z)-l-methyl-2-phenylethylene points to a one-step reaction. The very low Hammett constant, -0.43, determined with phenylethylenes substituted in the benzene ring, excludes polar intermediates. Yields of only a few percent are obtained in the reaction of aliphatic alkenes with (52). In the reaction of cyclohexene with (52), further amination of the aziridine to aminoaziridine (99) is observed. Instead of diphenylazirine, diphenylacetonitrile (100) is formed from diphenylacetylene by NH uptake from (52) and phenyl migration. 

To a solution of 5.1 g (20 mmol) 6-(l-methyl-2-nitroethyl)-l-(4-morpholinyl)-l-cyclohexene in 10 mL of ethanol are added, with cooling, 50 mL of 10% aq hydrochloric acid. The mixture is stood at r.t. for 12 h, the solvent is removed under reduced pressure and the residue is extracted with diethyl ether. The ethereal extract is evaporated leaving the crude title compound as a brown oil yield 3.0 g (80%) which is purified by distillation pale yellow oil, bp 128- 130°C/0.8 Torr nji,5 1.4808. The product is unstable and darkens after a short period of storage. 

Cyclohexanones, 2-alkyl-5 methyl-, 56 Cyclohexene, 34 Cyclohexene, 1,6-dibromo-, 34 CYCLOHEXENE, 3-METHYL-, 101 Cyclohexene, 1-phenyl- [Benzene, (1-eyclohexen-l-yl)-], 106 2-Cyclohexen-l-ol, 2-bromo-, 34 2-Cyclohexen-l-ol, 3-methyl-, 101 2-Cyclohexen-l-one, 2-allyl-3-methyl-[2-Cyclohexen-l-one, 3-methyl-2-(2-piopenyl)-], 55... 

Methyl-3-penten-2-ol 6. The vinyl group and the allyl group. 2-Methyl-2-cyclohexen-l-ol... 

A unique system for catalytic silaboration of allenes, in which a catalytic amount of organic halide is used as a crucial additive, has been reported (Equation (86)).232 In the presence of Pd2(dba)3 (5 mol%) with 3-iodo-2-methyl-2-cyclohexen-l-one (10mol%), reactions of terminal allenes with a silylborane afford /3-silylallylboranes in good yields with excellent regioselectivity. It is worth noting that the addition takes place at the terminal C=C bond in contrast to the above-mentioned palladium-catalyzed silaboration. The alkenyl iodide can be replaced with iodine or trimethylsilyl iodide. The key reaction intermediate seems to be silylpalladium(n) iodide, which promotes the insertion of allenes with Si-C bond formation at the central -carbon. 

We have resolved racemic 5-methyl-2-cyclohexen-l-one by reaction in the presence of catalytic amounts of cinchonidine using a 1.5 L0 molar ratio of enone to thiophenol (excess enone) in benzene (55). The reaction (eq. [11]) was carried out at room temperature for 18 hr. The purified unreacted cyclohexenone had a rotation [a]2,578 of +47° (c = 1.0, CC14), indicating an optical purity of 59% and the S configuration. Thus the R isomer reacts faster with the thiophenol under these conditions. Sharpless (57) points out that even small differences in relative rate (e.g., 5-10) can provide useful amounts of a substance with high... 

Ethylcyclop entanon e 3-Pentyl cyclopentanone 6-Methyl-3,5-heptadien-2-one 6-Methyl-2-cyclohexen-l-one 2,3-Dihydrocarvone Unidentified dimethylacetophenone 2-Butyrylfuran Dimethyl disulfide 2,6-Dimethylpyridine Isobutylbenzene Unidentified acetal (mol mass 154) Isobutyronitrile... 

Methyl-2-cyclohexen-l-one 2-Cyclohexen-l-one, 3-methyl- (8,9) (1193-18-6) (E)-Methyl crotonate Crotonic acid, methyl ester, (E)- (8) 2-Butenoic acid, methyl ester, (E)- (9) (623-43-8)... 

Methyl-2-cyclohexen-l-one was purchased from Aldrich-Europe, but is easily prepared from ethyl acetoacetate and paraformaldehyde. ... 

Das ziemlich einfach herstellbare 1 -Hydroxy- 1-piperidino-cyclopropan kann in Gegen-wart von Titan(IV)-chlorid in einer Variante der Mannich-Reaktion als Aquivalent von Cyclopropanon/Piperidin dienen nach der anzunehmenden in-situ-Umwandlung in 1-Cyclopropyliden-piperidinium-chlorid erfolgen Reaktionen z.B. mit 1-Trimethylsiloxy-cyclohexen zu 2-Oxo-l-(l-piperidino-cyclopropyl)-cyclohexan (63%) und mit 1-Methyl-pyrrol bzw. Indol zu l-Methyl-2-( 1-piperidino-cyclopropyl)-pyrrol (65%) bzw. 3-(l-Pipe-ridino-cyclopropyl)-indol (84%)2 ... 

Ethoxy-6-methyl-2-cyclohexen-l-one 2-Cyclohexen-l-one, 3-ethoxy-6-methyl-(10) (62952-33-4)... 

A 1-M hexane solution of di isobutyl aluminum hydride (400 mL, 0.40 mol) (Note 10) is added dropwise with stirring at 0°C oxer a 1-hr period. The solution is stirred for 2 additional hr at 0°C. To quench the reaction 200 mL of methanol is carefully added to the stirred reaction mixture, followed slowly at first then more rapidly with 400 mL of water and then 300 mL of 10 sulfuric acidt solution. After the mixture is stirred for 10 min, it is transferred to a separatory funnel and 500 mL of 10% sulfuric acid solution is added. The separatory funnel is shaken vigorously for 5 min and the organic phase 1s separated. The aqueous phase is extracted four times with 300 mL of diethyl ether. The organic phases are combined and washed twice with 300 mL of saturated sodium bicarbonate solution, twice with 300 mL of water, twice with 300 mL of brine, and dried over magnesium sulfate. Solvent removal on a rotary evaporator followed by short path distillation at reduced pressure affords 31-34 g (40-44%, based on 3-ethoxy-6-methyl-2-cyclohexen-l-one) of 4-(E-l,2-dichlorovinyl )-4-methy 1-2-cyclohexen-l-one (1) as a colorless oil, bp 75-78°C (0.1 mm) (Note 11). 

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