Patent ID: 7153999

Claim:
A method for producing a dimethylolcarboxylic acid represented by the following formula 1: wherein R is a C 1 -C 4 alkyl group, which comprises: a step A for reacting trimethylolalkane represented by the following formula 2: wherein R is as defined above, with formaldehyde in the presence of an acidic catalyst, thereby producing a cyclic formal represented by the following formula 3 having a formal protecting group: wherein R is as defined above; a step B for oxidizing the cyclic formal produced in the step A using nitric acid as an oxidizing agent in the presence or absence of a catalyst, thereby producing a cyclic carboxylic acid represented by the following formula 4: wherein R is as defined above; and a step C for cleaving the formal protecting group of the cyclic carboxylic acid produced in the step B to obtain the dimethylolcarboxylic acid of the formula 1.