The effect of solvents on the reduction of esters was examined with readily available sodium borohydride which is known to be incapable of reducing such functional groups. In mixed solvents of t-butyl alcohol–methanol or tetrahydrofuran–methanol, various carboxylic esters and lactones were found to be reduced by sodium borohydride to the corresponding alcohols or diols in high yields. Slow addition of methanol to the refluxing mixture of ester ...
