described herein are improved methods for the preparation of 5 - and 6 - membered cyclic mono and diesters of sugar alcohols and anhydrosugar alcohols by reaction with an organic acid rcooh over a solid acidic substrate . the process is adaptable to a continuous process for simultaneously making and separating the cyclic esters from the sugar alcohols and anhydrosugar alcohols under mild conditions using the solid acid substrate as both the catalyst and a chromatographic bed for separation . the reactions are performed at mild temperatures of 70 ° c . to 100 ° c . and the formation of the cyclic esters is nearly quantitative . also described is a method for making 5 - and 6 - membered cyclic mono and diesters of sugar alcohols and anhydrosugar alcohols using microwave irradiation in the presence of the organic acid .