Andrographolide (I) is protected as the acetonide (II) upon treatment with 2,2-dimethoxypropane and pyridinium p-toluenesulfonate. Esterification of the remaining free hydroxyl group of (II) with pivaloyl chloride provides the pivalate ester (III). The acetonide group of (III) is then removed by hydrolysis with 70 % AcOH to furnish the desired 14-pivaloyl andrographolide. (1,2)