Regioselective functionalization of unprotected myo-inositol by electrophilic substitution

Unprotected myo-inositol was treated with various electrophiles, such as aroyl chlorides, tosyl chloride and tert-butyldiphenylsilyl chloride in a solution of LiCl/DMA or DMSO to afford regioselectively 1,3-di-O-substituted or racemic 1-O-substituted derivatives, depending on a quantity of reagents and reaction time. α-Unbranched alkanoic acid anhydrides in LiCl/DMA in the presence of triethylamine were suitable for acylation of myo-inositol, in contrast to the fact that acylation using alkanoyl chlorides in aprotic polar solvents generally does not proceed well due to decomposition of the reagents by the reaction with the solvents.

El-X: carboxylic chlorides and anhydrides, sulfonyl chlorides, Ph2P(O)-Cl, (n-BuO)2P(O)-Cl, chlorosilanes