Selectivity switch in the catalytic functionalization of nonprotected carbohydrates: selective synthesis in the presence of anomeric and structurally similar carbohydrates under mild conditions.

A catalytic process for the chemo- and regioselective functionalization of nonprotected carbohydrates has been developed. This novel process allows selective thiocarbonylation, acylation, and sulfonylation of a particular hydroxy group in a particular carbohydrate in the simultaneous presence of structurally similar carbohydrates such as anomers. In addition, the chemoselectivity can be switched by regulating only the length of the alkyl chain in the organotin catalyst.