2‐[Dimethyl(2‐naphthylmethyl)silyl]ethoxy Carbonate (NSEC) as a New Mode of Hydroxyl Group Protection*

* In memory of Professor Jacques H. van Boom

Abstract

2‐[Dimethyl(2‐naphthylmethyl)silyl]ethoxy carbonate (NSEC) is a novel protecting group to mask hydroxyl groups. NSECCl is available in three steps from chlorodimethylvinylsilane and 2‐(bromomethyl)naphthalene. Introduction and removal of the NSEC group are performed easily and rapidly in the presence of most protecting groups currently used in carbohydrate chemistry. The removal of NSEC can be carried out under mild conditions in the presence of various ether and ester protecting groups. Additionally, the NSEC group is stable to glycosylation conditions using glycosyl phosphates. The synthesis of disaccharide 18 containing NSEC has been accomplished.

* In memory of Professor Jacques H. van Boom

Keywords:

• Carbonate
• Carbohydrates
• Deprotection
• Glycosylation
• Oligosaccharides
• Silyl protecting group

Acknowledgments

We gratefully acknowledge financial support of the Swiss National Science Foundation (Grant Nr. 200021–101593 “Automated Solid‐Phase Synthesis of Oligosaccharides”), the ETH Zürich, and the Deutsche Forschungsgemeinschaft (Emmy Noether fellowship for A. H.).

Notes

* In memory of Professor Jacques H. van Boom