Development of Ketoside-Type Analogues of Trehalose by Using α-Stereoselective O-Glycosidation of Ketose

The stereoselective synthesis of ketoside-type analogues of trehalose is described. O-Glycosidation of hept-2-ulopyranose with trimethylsilyl α-pyranoside promoted by trimethylsilyl trifluoromethanesulfonate afforded α-ketopyranosyl α-aldopyranosides exclusively. α-Ketopyranosyl β-aldooyranosides and α-ketopyranosyl α-ketopyranosides were also synthesized in a similar manner. The benzyl protecting groups of the hydroxy moieties were removed by hydrogenolysis to afford fully deprotected trehalose analogues.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)