In addition to lithium aluminum hydride, organomagnesium halides, known as Grignard reagents, convert acid halides to alcohols. Unlike the first approach, where the final product is a primary alcohol, reduction with the Grignard reagent yields a tertiary alcohol. The reaction requires two equivalents of the Grignard reagent and proceeds via a ketone intermediate. Since the alkyl–magnesium bond is highly polar, the alkyl carbon acquires a carbanionic character and functions as a nucleophile. The first step of the mechanism begins with a nucleophilic attack by the Grignard reagent at the carbonyl carbon, forming a tetrahedral intermediate. In the second step, the carbon–oxygen double bond is reconstructed, and the halide ion departs as a leaving group to yield a ketone. Next, the ketone is attacked by another equivalent of the Grignard reagent, generating an alkoxide intermediate. Lastly, protonation of the alkoxide drives the reaction to completion, forming a tertiary alcohol as the final product.