A fully enzymatic esterification/transesterification sequence for the preparation of symmetrical and unsymmetrical trehalose diacyl conjugates†
Monoacyl and diacyl trehalose were synthesized in two steps from trehalose and carboxylic acids. The carboxylic acids were converted first into the corresponding 2,2,2-trifluoroethyl esters through a biocatalyzed esterification. The acyl donor was then transferred to the disaccharide through biocatalyzed transesterification. Thanks to microwave reaction conditions the transesterification proceeded selectively to the monoacyl trehalose or to the diacyl counterparts depending on the sole amount of the acyl donor. These reaction conditions were also applied for the preparation of unsymmetrical diacyl trehalose in a fully enzymatic sequence.