Reactions of 1-alkoxycarbonylpyridinium salts with nucleophiles: stereoelectronic restrictions on carbonyl activation of α-nucleophilic attack

Abstract

The lack of reactivity of N-(α-ethoxycarbonylalkyl)-2,4,6-tri-substituted pyridinium salts toward nucleophilic displacement of the N-substituent is ascribed to stereoelectronic effects. Although such esters undergo ready base hydrolysis to give the corresponding acids, they are highly resistant to attack by other nucleophiles at the CO function; this behaviour is rationalised.