Preparation method for 2,2-dimethylol alkanoic acid

The invention relates to a preparation method for 2,2-dimethylol alkanoic acid. The preparation method comprises the following steps: reacting alkylnitrile and chloromethyl methyl ether under the effect of an alkali to generate 2,2-dimethoxy alkylnitrile; carrying out acidic hydrolysis on 2,2-dimethoxy alkylnitrile, so as to obtain the product 2,2-dimethylol alkanoic acid. The process is simple and convenient to react; 2,2-dimethylol alkanoic acid has the advantages of high total yield and high purity; the technical problem that the product is difficult to prepare and purify is overcome.