Reaction of ethyl 2,4-dibromo-2,4-dimethyl-3-oxopentanoate with zinc and aldehydes

Ethyl 2,4-dibromo-2,4-dimethyl-3-oxopentanoate reacts with zinc and aliphatic or aromatic aldehydes to furnish 3,5,5-trimethyl-6-R-2,3,5,6-tetrahydropyran-2,4-diones as a single geometrical isomer that in polar solvents converts into enol form.     

Synthesis of 6-hetaryl-5,5-dialkyl-3,3-dimethyl-tetrahydropyran-2,4-diones by Reformatsky Reaction

Zinc enolates derived from ethyl 4-bromo-2,2,4-trimethyl-3-oxopentanoate and 4-bromo-4- ethyl-2,2-dimethyl-3-oxohexanoate react with 2-furan-, 2-thiophene-, 1-(3-nitrophenyl)-2-pyrrole-, 1-acyl-3-indole-, and 2-pyridinecarbaldehydes to give the corresponding 6-hetaryl-5,5-dialkyl-3,3-dimethyltetrahydropyran-2,4-diones.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1549–1551.Original Russian Text Copyright © 2004 by Shchepin, Korzun, Sazhneva.     

Kinetics of decomposition of the liquid phase of the ternary system LiOH-H2O2-H2O in the presence of the solid phase of Li2O2 · H2O

The kinetics of decomposition of hydrogen peroxide in the liquid phase of the ternary system LiOH-H₂O₂-H₂O was studied in the presence the solid phase of Li₂O₂·H₂O and without it. The main kinetic parameters of the processes studied were determined.     

Alkylation with Substituted Phenacyl Bromides of Sodium Enolates from 6-Aryl-3,5,5-trimethyl-2,3,5,6-tetrahydropyran-2,4-diones

Russian Journal of Organic Chemistry -