Reactivity of α-hydroxy Acids towards Piperidinium Chlorochromate Oxidation
نویسندگان
چکیده
The kinetics of oxidations of α-hydroxy acids such as glycolic acid, lactic acid and mandelic acids with piperidiniumchlorochromate has been studied in aqueous acetic acid medium. The reaction order is one with respect to oxidant, substrate and fractional order with respect to hydrogen ion concentration. Decrease in dielectric constant of the medium increases the rate of reaction. No appreciable change in the rate is observed by increasing the ionic strength of the medium. The reaction does not induce the polymerization of acrylonitrile. From the kinetic data obtained, the activation parameters have been calculated and plausible mechanism has been proposed. The relative reactivity of the order is α-hydroxy acids viz., glycolic acid < lactic acid<mandelic acid.
منابع مشابه
A straightforward approach towards combined α-amino and α-hydroxy acids based on Passerini reactions
Complex amino acids with an α-acyloxycarbonyl functionality in the side chain are easily available through epoxide opening by chelated enolates and subsequent oxidation/Passerini reaction. This protocol works with both, aldehyde and ketone intermediates, as long as the ketones are activated by electron-withdrawing groups. In principle Ugi reactions are also possible, allowing the generation of ...
متن کاملAn efficient synthesis of tetramic acid derivatives with extended conjugation from L-Ascorbic Acid
BACKGROUND Tetramic acids with polyenyl substituents are an important class of compounds in medicinal chemistry. Both solid and solution phase syntheses of such molecules have been reported recently. Thiolactomycin, a clinical candidate for treatment of tuberculosis has led to further explorations in this class. We have recently developed an efficient synthesis of tetramic acids derivatives fro...
متن کاملMicrowave-Assisted Oxidation of Alcohols Using Wet Alumina Supported Ammonium Chlorochromate in Solventless System
Ammonium Chlorochromate in Solventless System Majid M. Heravi* and Maryam M. Aghayan Chemistry and Chemical Engineering Research Center of Iran. P.O. Box 14335-186, Teheran, Iran. Fax: 0098(21) 8037185, E-mail: [email protected] Z. Naturforsch. 54b, 815Ð817 (1999); received December 2, 1998 Oxidation, Alcohols, Carbonyl Compounds, Wet Alumina, Solventless System, Ammonium Chlorochromate A simp...
متن کاملElectrochemical Dissolution of Iron(III) Hydroxy-Oxides: More Information About the Particles
The process of reductive dissolution of α-Fe2O3, Ba-hexaferrite, α-FeOOH, γ-Fe2O3, γ-FeOOH, and ferrihydrite can be monitored continuously by abrasive stripping voltammetry and chronoamperometry to obtain information about homogeneity of reactivity and about the particle size of the pure phases and mixtures. Phase parameters (rate constant and charge transfer coefficient) and the geometrical fa...
متن کاملAn Investigation of the Reactions of Substituted Homoallylic Alcohols with Various Oxidation Reagents
Substituted homoallylic alcohols have been synthesised both by [2,3]-Wittig rearrangement of unsymmetrical bis-allylic ethers and reaction of alkenyl chloromethyl oxiranes with Mg/THF. These substrates were then oxidized using four different oxidants. When the substituted homoallylic alcohols were oxidized with pyridinium chlorochromate or zinc chlorochromate nonahydrate the corresponding carbo...
متن کامل