Phenolics compounds such as phenol in genera were stable at the esterification conditions, but the phenolics with a carbon–carbon double bond, such as 2-methoxy-4-vinylphenol,
were converted to other compounds, probably due to methanolysis or the involvement of 2-methoxy-4-vinylphenol in the electrophilic addition reactions (Hu et al., 2012b).