Organolithium reagents with esters

With organolithium reagents, stable intermediates are produced by addition to a carboxylic acid. On workup, these intermediates produce ketones. As with Grignard reagents, the reaction of organolithium reagents with esters produces tertiary alcohols because the intermediates decompose to ketones under the reaction conditions. The mechanisms for these processes are illustrated in the examples that follow. 

Conjugate addition to a, -unsaturated esters.1 The unsaturated esters of this phenol undergo ready conjugate addition with a variety of organolithium reagents, with t-butyllithium providing the only exception. The adducts are oxidatively hydrolyzed to carboxylic acids by CAN (10, 162). 

Reactions of either Grignard or organolithium reagents with most aldehydes, ketones, or esters produce alcohols. Reactions of organolithium reagents with carboxylic acids, or of Grignard reagents with nitriles, produce ketones. 

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