EFFECT OF THE NATURE OF SOLID METAL FLUORIDES ON THE ALKYLATION KINETICS OF CH-ACIDS IN THE PRESENCE OF ONIUM SALTS

Article abstract of DOI:10.1007/BF00962425

The selective C-alkylation of ethyl 2-methylacetoacetate by prenyl chloride in the presence of solid metal fluorides proceeds at room temperature with yields of from 2.5 to 87.5percent depending on the nature of the deprotonating agent.The alkylation rate increases in going from LiF to CsF.A linear correlation was found between the activation free energy for thealkylation reaction and the crystal lattice energy of the solid metal fluorides.Ion exchange was not observed between tetrabutylammonium chloride and solid KF, CsF, and CaF2 in acetonitrile.The extent of the exchange with KF*2H2O over 10 h did not exceed 6percent.Deprotonation of ethyl 2-methylacetoacetate by the action of the solid metal fluorides was not observed.Loss of the CH-acid is found in the presence of an onium salt, which varies upon changing the nature of the deprotonating agent; LiF ca.NaF ca.KF (30percent), RbF (54percent), CsF (90percent), CaF2 (35percent).