2-DICHLOROMETHYL-1,3-DIOXOLAN-2-YL ORTHOESTERS. A POTENTIAL PROTECTING GROUP FOR SUGAR DERIVATIVES

Abstract

Reactions of 2-dichloromethylene-1,3-dioxolane (2) with acetal protected sugar derivatives in neutral media gave 2-dichloromethyl-1,3-dioxolan-2-yl orthoesters. These orthoesters are readily hydrolysed under mild acidic conditions offering a new method for the preparation of readily removable protecting groups. This strategy was realised in the preparation of 6-O-acetyl-3,5-di-O-methyl-1,2-O-isopropylidene-α-d-glucofuranose.

Keywords:

• Sugar derivatives
• Protecting groups
• Orthoesters
• Ketene acetals

ACKNOWLEDGMENTS

The authors are grateful for the support of TUBITAK (The Scientific and Technical Research Council of Turkey) and The Graduate School of Natural and Applied Sciences, Ege University.