Abstract
Synthesis of two LewisX 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.
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.