Processes for producing a compound represented by the formula (1), which includes an acrylic acid derivative and is useful as an agricultural chemical or medicine. One of the processes comprises the step of formulating a compound (3) and converting the OH of the resultant compound (2) into OR″. The first step comprises reacting a formic or orthoformic ester in the presence of a Lewis acid and a base. The second step comprises reacting the compound with R″OH or with R″OH and CH(OR″)
3
under acidic conditions or using a phase-transfer catalyst in a two-phase system and regulating the base and the concentration thereof to stereoselectively synthesize the target compound. In another, process, the compound is efficiently produced without isolating the compound. The compound can also be produced without the compound (2).
1