2.2.3. (E)-Methyl-3-methoxy-2-(2-hydroxyphenyl)acrylate (**4**)

A mixture of 10 wt. % Pd/C (0.18 g, 0.085 mmol) was added into a solution of compound **4** (1.00 g, 3.36 mmol) in 30 mL EtOAc. The mixed solution was then stirred under a H<sup>2</sup> atmosphere (1 atm) at 35 ◦C for 12 h. Then, the reaction mixture was filtered and the filtrate was concentrated under vacuum. The residue was further purified by silica gel column chromatography (1:3 EtOAc /hexane) to afford **4** (1.34 g, 95.4%).
