preferred_name: an alcohol + a carboxylate + H(+) => a carboxylic ester + H2O
preferred_name_lc: an alcohol + a carboxylate + h(+) => a carboxylic ester + h2o
label: an alcohol + a carboxylate + H(+) => a carboxylic ester + H2O
label_lc: an alcohol + a carboxylate + h(+) => a carboxylic ester + h2o