Organo-zinc Promoted Diastereoselective C-Arylation of 1,2-Anhydrosugars from Arylboronic Acids.

α-C-arylglycosides can be obtained through the addition of aryl zinc reagents to sugar epoxides. The required aryl zinc nucleophiles can be easily obtained from the corresponding boronic acids by B-Zn exchange and attack sugar 1,2 epoxides in a highly diastereoselective fashion to generate 1,2-cis-α-hexapyranosyl aryl glycosides under ligand- and base-free conditions.