Synthesis of Two Lewis^X Trisaccharides Using Regiospecific Glycosylation Reactions

Abstract

Synthesis of two Lewis^X trisaccharides, namely, 2‐(trimethylsilyl)ethyl 2,3,4,6‐tetra‐O‐acetyl‐β‐D‐galactopyranosyl‐(1→4)‐6‐O‐benzyl‐2‐deoxy‐3‐O‐(2,3,4‐tri‐O‐benzyl‐α‐L‐fucopyranosyl)‐2‐phthalimido‐β‐D‐glucopyranoside and 2‐(trimethylsilyl)ethyl 2,3,4‐tri‐O‐acetyl‐6‐O‐t‐butyldiphenylsilyl‐β‐D‐galactopyranosyl‐(1→4)‐6‐O‐benzyl‐2‐deoxy‐3‐O‐(2,3,4‐tri‐O‐benzyl‐α‐L‐fucopyranosyl)‐2‐phthalimido‐β‐D‐glucopyranoside, has been achieved using a regiospecific glycosylation strategy under NIS‐TfOH activation. Two trisaccharides were prepared from monosaccharides without any protecting group manipulation.

Keywords:

• Synthesis
• Trisaccharide
• Lewis^X
• N‐Iodosuccinimide
• Trifluoromethanesulfonic acid

Acknowledgments

We are grateful to DST (Govt. of India) for financial assistance and CSIR for a J.R.F to D.M. The authors thank Dr. R. Mukhopadhyay for spectral analysis. We are indebted to Pradip Kr Roy of our department for his interest in this work.