Final answer:
The general mechanism when reacting acid chlorides or esters with RLi or RMgX involves a nucleophilic acyl substitution reaction, resulting in the substitution of the R group for the leaving group.
Step-by-step explanation:
The general mechanism when reacting acid chlorides or esters with RLi or RMgX involves a nucleophilic acyl substitution reaction. In this reaction, a nucleophile, such as RLi or RMgX, attacks the carbon atom of the acid chloride or ester, while a leaving group, such as a halide ion, leaves. This results in the substitution of the R group for the leaving group.
For example, when an acid chloride reacts with RLi, the nucleophile RLi attacks the carbonyl carbon of the acid chloride, displacing the chloride ion as the leaving group. The resulting product is an alkyl ketone.
Similarly, when an ester reacts with RMgX, the nucleophile RMgX attacks the carbonyl carbon of the ester, displacing the alkoxide ion as the leaving group. The resulting product is a tertiary alcohol.