Methylcy clohexanone

Gall, M. House, H. O. The formation and alkylation of specific enolate anions from an unsymmetrical ketone 2-benzyl-2-methylcy-clohexanone and 2-benzyl-6-methylcyclohexa-none. Org. Synth. 1988, Coll. Vol. VI, 121-130. 

Enamines are ambident nucleophiles giving C- and N-alkylated products. Acceptable yields of C-alkylated products are obtained by using reactive alkyl halides such as CH3I, ally lie and benzylic halides, and a-halocarbonyl compounds. The resultant iminium ion intermediates no longer behave as a enolates, thus dialkylation is avoided. The stereochemical course of alkylation of the enamine derived from 2-methylcy-clohexanone is depicted below. The reason for the preferred parallel alkylation via a boat-like transition state over antiparallel alkylation via a chair-like transition state is the synaxial RX // CH3 interaction in the latter case. ... 

The consideration of the development of torsional strain in the transition state for nucleophilic addition afforded an explanation for product distributions observed in the addition of nucleophiles to substituted cyclohexanones. Dauben and co-workers reported that reduction of 4-methylcy-clohexanone with LiAlH4 produced 81% of the trans alcohol and 19% of the cis isomer. With 4-f-butylcyclohexanone, a conformationally more rigid struc-... 

The formation of pyrrolidine enamines from 2-alkylcycloalkenones is highly regiospecific [14] and alfords the less substituted enamines. Thus, 2-methylcy-clohexanone yields a mixture of 6-methyl-1 -pyrrolidinocyclohexene (90%) and 2-methyl-1-pyrrolidinocyclohexene (10%), which is then converted to 3-meth-ylcyclohexene (Eq. 24.7) [13]. 

The selective hydrogenation of propyne to propene has been studied over porous ultraflltration polymeric membranes of polyacrylonitrile (PAN), polyetherimide (PEI) or polyamideimide (PAI) or over poly(acrylic acid) membranes, treated with palladium acetate. Similarly, porous PVDF membranes, also loaded with palladium particles, were used in hydrogenation flow-through experiments of methylenecyclohexane to methylcy-clohexanone. The hydrogenation of viscous liquids such as vegetable oils could also be performed in flow-through experiments over porous polymeric membranes loaded with palladium or platinum particles. " ... 

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