Efficient Chemical Syntheses of Branched Cyclomalto‐Oligosaccharides Using the Trichloroacetimidate Method

Abstract

Glycosylation using the trichloroacetimidate method was investigated in order to synthesize branched cyclomalto‐oligosaccharides (cyclodextrins, CDs). We examined the chemical syntheses of galactosyl CDs, directly β‐linked to the CD ring, which could not be synthesized by enzyme catalyzed reactions. We prepared 6‐O‐(d‐galactosyl)‐γCD and 6‐O‐(d‐mannosyl)‐γCD as basic model compounds using a combination of protecting groups on the glycosyl donor, catalysts to synthesize imidate derivatives, and catalysts for glycosylation. The configurational isomers were determined by HPLC and NMR spectroscopy.

Keywords:

• Glycosylation
• Galactosyl‐γCD
• Mannosyl‐γCD

Acknowledgments

We thank Prof. M. Yamaki and her staff (Mukogawa Women's University) for recording and measuring the NMR spectra.

Additional information

Notes on contributors

Kyoko Koizumi

Deceased August 16, 2000.