Das Allopolarisierungsprinzip und seine Anwendungen, VI [1] Die Alkylierung von Enolatanionen: Polarität und Regioselektivität / The Allopolarization Principle and its Applications, VI [1] The Alkylation of Enolate Anions: Polarity and Regioselectivity

Abstract

Abstract The O/C methylation ratio in the reaction of sodium enolates with dimethylsulfate depends on the polar(electronic) effect of substituents. The relative π-charge density Px/y = 1x/1y can be used as a measure for the polarity of ambifunctional anions; in case of enolate anions Po/c = 1o/1c-The change of the regioselectivity Sf = log Qo/Qc in the alkylation of enolates is a function of the change in the polarity Po/c; ⊿Sf = f (⊿Px/y). The polar effect of substituents influences the charge control during the alkylation process via a change of the polarity of the enolate system: The higher the polarity of the anion, the stronger the charge control and the higher the yield of enol ether (O-alkylation).