521087-52-5Relevant articles and documents
Chromate oxidation of α-nitro alcohols to α-nitro ketones: Significant improvements to a classic method
Elmaaty, Tarek Abou,Castle, Lyle W.
, p. 1458 - 1461 (2007/10/03)
A series of eight alkyl and aryl α-nitro ketones were prepared by the potassium dichromate oxidation of the corresponding nitro alcohols. Short reaction times allowed for the easy isolation of pure nitro ketones that are devoid of starting materials and/o
Enantiomerization study of some α-nitroketones by dynamic high-resolution gas chromatography
Gasparrini, Francesco,Pierini, Marco,Villani, Claudio,De Maria, Paolo,Fontana, Antonella,Ballini, Roberto
, p. 3173 - 3177 (2007/10/03)
The kinetics of the reversible enantiomer interconversion of 3-nitrobutan-2-one (1), 3-nitropentan-2-one (2), and 2-nitropentan-3-one (3) have been studied by dynamic high-resolution gas chromatography (DHRGC) by using a β-cyclodextrin derivative chiral stationary phase; the process occurs via enolization of the keto forms. The DHRGC experiments involving the studied nitroketones and the chiral stationary phase show chromatographic profiles with a typical interconversion plateau in the temperature range between 130 and 160 °C. Computer simulation of the experimental chromatographic elution profiles was employed for the determination of rate constants and the corresponding enantiomerization barriers (k, ΔG#(T), ΔH#, and ΔS#). The highly negative entropy of activation (ΔS# values from -19 to -37 cal mol-1 K-1) points to a transition state (TS) with large charge separation. The obtained results for 1-3 show the dramatic effect of an α-nitrosubstituent on the rate of enolization of simple ketones, when compared with those for 3-chloro-2-butanone and 3-methyl-2-pentanone. To get some information on the separate contributions of the stationary liquid phase and the mobile gas phase on the studied process, some DFT ab initio calculations have been performed for the same compounds.
A one pot, solvent-free synthesis of acyclic α-nitro ketones through the nitroaldol reaction
Ballini, Roberto,Bosica, Giovanna,Parrini, Mauro
, p. 7963 - 7964 (2007/10/03)
Acyclic α-nitro ketones are easily obtained in one pot, through a solvent-free procedure by nitroaldol (Henry) reaction on neutral alumina, then in situ oxidation of the nitroalkanol using wet alumina supported chromium(VI) oxide.
