Reactivity Controlled by Lattice Interactions in Crystal:  Intermolecular Acyl Transfer in (±)-2,4-Di-<i>O</i>-benzoyl-<i>myo</i>-inositol 1,3,5-Orthoformate

Abstract

(±)-2,4-Di- O -benzoyl- myo -inositol 1,3,5-orthoformate, on heating in the presence of a base, undergoes transesterification to give 2,4,6-tri- O -benzoyl- myo -inositol 1,3,5-orthoformate and 2- O -benzoyl- myo -inositol 1,3,5-orthoformate in the solid state. The same reaction can also be performed by microwave irradiation instead of heating. The crystal structure of the dibenzoate reveals that the screw-axis-related molecules have the hydroxyl and the carbonyl groups ideally oriented for the reaction and gives a close picture of how such a reaction proceeds in enzymes. The structure of the corresponding acetate, (±)-2- O -benzoyl-4- O -acetyl- myo -inositol 1,3,5-orthoformate, lacks this geometry and hence is unreactive in the solid state. Both the acetate and the benzoate undergo base-catalyzed transesterification in solution.