Cyclohexanones from

There is another aspect to the question of the reactivity of the carbonyl group in r ck)hexanone. This has to do with the preference for approach of reactants from the axial ir equatorial direction. The chair conformation of cyclohexanone places the carbonyl coup in an unsynunetrical environment. It is observed that small nucleophiles prefer to roach the carbonyl group of cyclohexanone from the axial direction even though this is 1 more sterically restricted approach than from the equatorial side." How do the ctfcnaices in the C—C bonds (on the axial side) as opposed to the C—H bonds (on the equatorial side) influence the reactivity of cyclohexanone ... 

Preparation of 2-(Peifluorohexyl)cyclohexanone from Perfluorohexyl Iodide 143]... 

An alternative to cyclohexanones from phenols involves ring saturation to the alcohol, followed by oxidation 14). 

Oxidation of organic compounds by dioxygen is a phenomenon of exceptional importance in nature, technology, and life. The liquid-phase oxidation of hydrocarbons forms the basis of several efficient technological synthetic processes such as the production of phenol via cumene oxidation, cyclohexanone from cyclohexane, styrene oxide from ethylbenzene, etc. The intensive development of oxidative petrochemical processes was observed in 1950-1970. Free radicals participate in the oxidation of organic compounds. Oxidation occurs very often as a chain reaction. Hydroperoxides are formed as intermediates and accelerate oxidation. The chemistry of the liquid-phase oxidation of organic compounds is closely interwoven with free radical chemistry, chemistry of peroxides, kinetics of chain reactions, and polymer chemistry. 

Cyclopol A process for making cyclohexanone from benzene, the intermediates being cyclohexane and cyclohexanol. Developed and licensed by Polimex-Cekop. In 1997,20 percent of world demand for cyclohexanone was made by this process. 

Sun, H., Blatter, F. and Frei, H. (1996). Cyclohexanone from cyclohexane and 02 in a zeolite under visible light with complete selectivity. J. Am. Chem. Soc. 118, 6873-6879... 

MANGANESE-COPPER-CATALYZED CONJUGATE ADDITION OF ORGANOMAGNESIUM REAGENTS TO a,p-ETHYLENIC KETONES PREPARATION OF 2-(1,1-DIMETHYLPENTYL)-5-METHYL-CYCLOHEXANONE FROM PULEGONE (Cyclohexanone, 2-(1,1-dimethylpentyl)-5-methyl-)... 

A. S. Machado, A. Olesker, and G. Lukacs, Synthesis of two tetrasubstituted cyclohexanones from 6-deoxyhex-5-enopyranoside derivatives, Carbohydr. Res. 735 231 (1985). 

Fonseca G, Seoane GA (2005) Chemoenzymatic Synthesis of Enantiopure a-Substituted Cyclohexanones from Aromatic Compounds. Tetrahedron Asymmetry 16 1393... 

Scheme 4. Generation of cyclohexanone from cyclohexyl-hydroperoxide via a 1,2-H atom shift mechanism.

The production of Cyclohexanone from phenol was simplified when selective hydrogenation with Pd catalysts was made possible ([see Eq. 21.3)]. In this process, phenol is completely converted in the gas phase at 140 to 170°C and 1 to 2 bar using a supported Pd catalyst containing alkaline earth oxides (e.g., Pd-CaO/A Os). The selectivity to Cyclohexanone is greater than 95%46. 

Under vigorous conditions (100°C and 1000 psig) in 25% aqueous sulfuric acid, the yield of cyclohexanol plus cyclohexanone from dimethyl-aniline was 90, 75, and 13% over 5% palladium-, 5% rhodium-, and 5% platinum-on-carbon, respectively (33). The decreasing yield parallels the decreasing tendency for migration. Reductive hydrolysis is favored by substitution on the nitrogen atom attributed in part to the relative difficulty of hydrogenating hindered enamines. 

Scheme 9A Formation of cyclohexanone from aci-nitrocyclohexane by the Nef reaction.

Other recent repiorts of the automated synthesis of SP libraries of discretes include those of Wilson et al. (166), who prepared a library of more than 1000 aminohydantoins from a-hydrazino amino acids, amines, and aldehydes Perumattam et al. (167), who reported a 200-member library based on an anhydride template using anhydrides, primary amines, and a-amino acids Smith et al. (168), who described the synthesis of a library of more than 1000 piperazinediones from a-amino acids Crawshaw et al. (169), who presented a >200-member Ubrary of cyclohexanones from maleimides, nitrostyrenes, and aminobutadienes Shao et al. (170), who described a 96-member library of quina-zolinediones from anhydrides and amines Lebl et al. (21), presenting a 30,816-member... 

Cyclohexanol and cyclohexanone from cyclohexane with supported Co (s) as the catalyst. 

Commercial acetone dimethyl acetal and allyl alcohol from The Dow Chemical Company and cyclohexanone from Eastman Kodak Company were used without further treatment. 

See the section entitled Isolation of Cyclohexanone from Steam Distillate in the previous experiment to complete the reaction sequence. 

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