15598-80-8Relevant academic research and scientific papers
Unusual Solvent Effects in the Wittig Reaction of Some Ketones Indicating Initial One-Electron Transfer
Olah, George A.,Krishnamurthy, V.V.
, p. 3987 - 3990 (1982)
Investigation of the Wittig reaction of adamantanone, 1, and some other ketones in various solvent systems with alkylidenetriphenylphosphoranes indicates an initial one-electron transfer from the ylide to the carbonyl group.In hydrogen-donor solvents, the hydrogen abstraction from the solvents by the radical ions generated by the one-electron transfer competes considerably with the olefin-forming Wittig reaction, giving unexpected reduction of the carbonyl group.It is shown that such reductions become the major pathway when steric hindrance affects the usual olefin-forming Wittig reaction.
Diplogelasinospora grovesii IMI 171018, a new whole cell biocatalyst for the stereoselective reduction of ketones
Carballeira, Jose D.,Alvarez, Emilio,Campillo, Mercedes,Pardo, Leonardo,Sinisterra, Jose V.
, p. 951 - 962 (2007/10/03)
A screening of 416 strains (71 bacterial strains, 45 actinomycetes, 59 yeast, 60 basidiomycetes, 33 marine fungi and 148 filamentous fungi) has been performed to look for microorganisms that display reductase activity in the absence of oxidase activity. A new microorganism, Diplogelasinospora grovesii IMI 171018 (a nonpathogen strain), was isolated and showed very high activity and stereoselectivity in the reduction of cyclic ketones. The fungus was selected due to its selectivity towards monocyclic and bicyclic ketones and its easy culture conditions, which allow an easy scale-up. D. grovesii is more active in the reduction of conventional ketones than S. cerevisiae type II (from Sigma) and can work in the presence of high ketone concentrations (2 = 0.549) and can be used to explain and to predict the structure of ketones that can or cannot be reduced by this microorganism.
Organoboranes. 41. Reaction of Organoboranes with (Dichloromethyl)lithium. Scope and Limitations. Synthesis of Homologated Primary and Secondary Alcohols
Brown, Herbert C.,Imai, Toshiro,Perumal, P. Thirumali,Singaram, Bakthan
, p. 4032 - 4036 (2007/10/02)
Homologated primary alcohols were prepared from alkylboronic esters by the reaction with (dichloromethyl)lithium, LiCHCl2, followed by KIPBH treatment and oxidation.Homologated secondary alcohols were prepared from representative dialkylborinic esters and trialkylboranes by the reaction with LiCHCl2, followed by treatment with base and oxidation.The yields are generally good with both boronic and borinic esters.On the other hand, the reactions with trialkylboranes exhibited a sensitivity to large steric requirements in the trialkylborane reactant.
Steric Effects on Reaction Rates - III. Application of Force-Field Calculations to Chromic Acid Oxidation of Alcohols
Mueller, Paul,Blanc, Jacky,Lenoir, Dieter
, p. 1212 - 1220 (2007/10/02)
The rates of oxidation with chromic acid of 15 bi- and polycyclic secondary alcohols have been measured and correlated with strain changes calculated by the MM1-program between the alcohols and the corresponding ketones.A correlation of the same quality is obtained upon representation of OH-strain by CH3-strain.The significance of the correlations with respect to the oxidation mechanism as well as the limitations of the applicability of force-field calculations to reactivity problems are discussed.
ENZYMATIC "IN VITRO" REDUCTION OF KETONES VII. (1) Reduction rates and stereochemistry of the HLAD catalyzed reduction of 2-alkyl cyclohexanones, dimethyl cyclohexanones, cycloalkanones and bicycloalkanones.
Osselaer, T. A. Van,Lemiere, G. L.,Lepoivre, J. A.,Alderweireldt, F. C.
, p. 389 - 398 (2007/10/02)
Values for the rate constants of the catalytic step HLAD-NADH + ketone -> HLAD-NAD1+ + alcohol in the HLAD catalyzed reduction of some 2-alkyl cyclohexanones, geminal dimethyl cyclohexanones, cycloalkanones and bicyclic ketones are presented.Also the thermodynamic parameters of activation are given and they are compared with the activation parameters of the NaBH4 reduction leading to a better understanding of some forces at work in enzymatic catalysis.The results are rationalized in the same way as was previously done for the 3-alkyl and 4-alkyl cyclohexanones.A reaction model is obtained in which steric hindrances and hydrophobic zones are responsible for rate decreasing, respectively increasing interactions between enzyme and substrates.
