Acyl Substitution to Carbonyls

Loss of OMe will regenerate ethyl butanoate but loss of OEt will form methyl butanoate (and sodium ethoxide). This transesterification reaction is further complicated by the fact that ethoxide is nucleophilic and 

It is possible that the ketone product formed by reaction of a Grignard with an acid chloride or anhydride is. css reactive than those starting materials. If so, significant amounts of the ketone product can be isolated, but the yields are often low. With esters and amides, the ketone product is usually more reactive, very little ketone 1 isolated from the reaction mixture, and the ketone reacts further to form a tertiary alcohol. If a large excess 

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