SYNTHESIS OF THE TETRASACCHARIDE Glc α (1→3) Man α (1→2) Man α (1→2) Man α (OMe) AS INHIBITOR OF CALNEXIN BINDING TO GlcMan 9GlcNAc 21a

Abstract

Tetrasaccharide GlcMan 3 is an inhibitor of GlcMan 9GlcNAc 2 binding to calnexin, a chaperone protein involved in CFTR-ΔF 508 retention. A convergent route to its methyl glycoside, the title tetrasaccharide, was developed. The key building block Glc α (1→3) Man 6 was stereoselectively obtained by condensation of a trichloroacetimidate glucosyl donor with an ethyl thiomannopyranoside acceptor. Di-mannose moiety 10 and final compound 12 resulted from thioglycoside activations. a Dedicated to Prof. Joachim Thiem on the occasion of his 60th birthday.