- Reactions of hydrogen peroxide with acetylacetone and 2- acetylcyclopentanone
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A reaction of acetylacetone with equimolar amount of concentrated aqueous H2O2 in both organic solvents (ButOH, AcOH) and water at various temperatures gave the corresponding 3,5-dihydroxy-1,2- dioxolanes with different configuration of stereogenic centers. In the pres-ence of an excess of H2O2, 3,5-dihydroxy-1,2-dioxolanes were converted to a mixture of 5-hydroperoxy-3-hydroxy-1,2-dioxolanes and further to a mixture of dimeric 1,2-dioxolan-3-ylperoxides. All the peroxides formed exist in solutions as equilibrium mixtures with the starting reagents. A prolonged reflux of solutions of 3,5-dihydroxy-1,2-dioxolanes in ButOH in the presence of a large excess of H2O2 led to the skeletal rearrangements of the substrates to a mixture of propionic acid and hydroxyacetone, which underwent further oxidative transfor-mations. Unlike acetylacetone, 2-acetylcyclopentanone reacted with H2O2 in aqueous phase or in solutions in ButOH under thermodynamic or kinetic control with the formation of the corresponding 5-hydroperoxy-3-hydroxy- 1,2-dioxolanes, rather than 3,5-dihydroxy-1,2-di-oxolanes. Thermodynamically controlled process in solution in AcOH gave a mixture of all four possible hydroperoxyhydroxy-1,2-dioxolanes. These cyclic peroxides in solutions in ButOH or AcOH readily converted to a mixture of AcOH, glutaric, α-methyladipic, and α-hydroxy-α-methyladipic acids. An active α-hydroxylation of the substrate was observed upon reflux of a solution of 2-acetylcyclopentanone and H2O2 in AcOH.
- Novikov,Shestak
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p. 2171 - 2190
(2014/11/07)
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- Thermal and photochemical oxidation of 2-acetylcyclopentanone with atmospheric oxygen
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The major products of thermal (acetone, CaCl2 excess, reflux) and photochemical (acetone or CCl4, room temperature) oxidation of 2-acetylcyclopentanone with atmospheric oxygen are 2-acetyl-2- hydroxycyclopentanone, 2-acetyl-2-hydroxy
- Novikov,Shestak
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p. 1099 - 1110
(2013/07/26)
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