Cyclohexanone, preparation from cyclohexene

Another approach to achieve higher conversions is to start from cyclohexene, which is much more reactive than cyclohexane towards autoxidation [6], and can be prepared by hydrogenation of benzene over a ruthenium catalyst [7]. The higher reactivity of cyclohexene also allows for lower reaction temperatures thus further limiting overoxidation. The 2-cyclohexen-l-one product formed by decomposition of cyclohexenyl hydroperoxide can subsequently be hydrogenated to cyclohexanone. The net reaction stoichiometry is the same as the current process. We now report our results on the use of CrAPO-5, CrS-1 and other transition-metal substituted molecular sieves for the decomposition of cyclohexenyl hydroperoxide. 

The cyclohexylidene ketal has been prepared from dimethoxycyclohexane and TsOH HC(OEt)3, cyclohexanone, TsOH,EtOAc, heat, 5h, 78% l-(trimethylsiloxy)-cyclohexene, coned. HCl, 20°C, 10-30 min, 70-75% yield, cyclohexanone, TsOH, CUSO4/ , and 1-ethoxycyclohexene, TsOH, DMF. The cyclohexylidene derivative of a fra .v-l,2-diol has been prepared. Cyclohexylidene ketals may also be prepared directly from an epoxide with MTO catalysis. ... 

Other methods for the preparation of cyclohexanecarboxaldehyde include the catalytic hydrogenation of 3-cyclohexene-1-carboxaldehyde, available from the Diels-Alder reaction of butadiene and acrolein, the reduction of cyclohexanecarbonyl chloride by lithium tri-tcrt-butoxy-aluminum hydride,the reduction of iV,A -dimethylcyclohexane-carboxamide with lithium diethoxyaluminum hydride, and the oxidation of the methane-sulfonate of cyclohexylmethanol with dimethyl sulfoxide. The hydrolysis, with simultaneous decarboxylation and rearrangement, of glycidic esters derived from cyclohexanone gives cyclohexanecarboxaldehyde. 

The preparation of Pans-1,2-cyclohexanediol by oxidation of cyclohexene with peroxyformic acid and subsequent hydrolysis of the diol monoformate has been described, and other methods for the preparation of both cis- and trans-l,2-cyclohexanediols were cited. Subsequently the trans diol has been prepared by oxidation of cyclohexene with various peroxy acids, with hydrogen peroxide and selenium dioxide, and with iodine and silver acetate by the Prevost reaction. Alternative methods for preparing the trans isomer are hydroboration of various enol derivatives of cyclohexanone and reduction of Pans-2-cyclohexen-l-ol epoxide with lithium aluminum hydride. cis-1,2-Cyclohexanediol has been prepared by cis hydroxylation of cyclohexene with various reagents or catalysts derived from osmium tetroxide, by solvolysis of Pans-2-halocyclohexanol esters in a manner similar to the Woodward-Prevost reaction, by reduction of cis-2-cyclohexen-l-ol epoxide with lithium aluminum hydride, and by oxymercuration of 2-cyclohexen-l-ol with mercury(II) trifluoro-acetate in the presence of ehloral and subsequent reduction. ... 

Apart from the reaction of cyclohexanecarboxylic acid with methyllithium, cyclohexyl methyl ketone has been prepared by the reaction of cyclohexylmagnesium halides with acetyl chloride or acetic anhydride and by the reaction of methylmagnesium iodide with cyclohexanecarboxylic acid chloride. Other preparative methods include the aluminum chloride-catalyzed acetylation of cyclohexene in the presence of cyclohexane, the oxidation of cyclohexylmethylcarbinol, " the decarboxylation and rearrangement of the glycidic ester derived from cyclohexanone and M)utyl a-chloroj)ropionate, and the catalytic hydrogenation of 1-acetylcycIohexene. "... 

Materials. The complex RhCl(ttp) was prepared as described previously (6). Cyclohexanone was obtained from Mallinkrodt cyclohexene and 1-pentene were obtained from MCB. All other olefins and 1-octyne were purchased from ChemSampCo. The aluminum alkyls were obtained from Aldrich as 25% w/w solutions in toluene. Neat liquids used in the H-l NMR work were obtained from these solutions by removing the toluene under vacuum. Lithium dimethylamide, LiN(CH3)2, was obtained from Alpha/Ventron as a 10% w/w slurry in hexane. Hydrogen was passed through an Englehard Deoxo purifier and activated alumina before use. 

The reaction of NO with the double bonds of enamines also produces compounds containing the diazeniumdiolate functional group bound to carbon, and some of the compounds prepared in this way have the potential to serve as spontaneous NO donors [43]. The compounds chosen for study were enamines 1-4 derived from condensation of cyclopentanone or cyclohexanone with morpholine or pyrrolidine. When these enamines were dissolved in acetonitrile and treated with NO gas (5-atm pressure) at room temperature, a vigorous exothermic reaction resulted, accompanied by high uptake of NO and formation of a brown precipitate. Attempts to isolate the solid precipitates often resulted in rapid decomposition, with the release of large volumes of gaseous NO. At -78 °C in diethyl ether, the reaction of 4-(l-cyclohexen-l-yl) morpholine (IX) afforded a good yield of crystalline NO addition product (X) ... 

Li-thiophenoxide in tetrahydrofuran-hexane added at 25 to a stirred suspension of Cul in tetrahydrofuran, after 5 min. tert-butyllithium in pentane injected dropwise at -78 followed after 5 min. by a soln. of 2-cyclohexen-l-one in tetrahydrofuran, warmed to 0 , and the product isolated after 2 hrs. -> 3-tert-buiyl-cyclohexanone. Y 72%.-Li-(phenylthio)organocuprates are easily prepared, stable up to 0 , and allow easy work-up. They are particularly useful for the prepn. of a-subst. ketones from a,a -dibromoketones and of ketones from carboxylic acid chlorides. F. e., syntheses, and Li-heterocuprates(l) s. G. H. Posner, C. E. Whitten, and J. J. Sterling, Am. Soc. 95, 7788 (1973) convenient prepn. of Li-phenylthio-(alkyl)cuprates s. Synthesis 1974, 662 mixed Li-dialkylcuprates s. W. H. Mande-ville and G. M. Whitesides, J. Org. Chem. 39, 400 (1974). 

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