Synthesis and Structure Elucidation of Benzoylated Deoxyfluoropyranosides

Abstract

Benzoylated deoxyfluoropyranosides have been synthesized, starting with protected, unprotected, or fluorinated precursors. Fluorination of eight derivatives was compared using DAST and Deoxo-Fluor as reagents. Deoxo-Fluor was found to be especially useful in the fluorination of methyl 2,3,4-O-tribenzoyl α-D-mannopyranoside and β-D-glucopyranoside, resulting in better yields and avoiding the 1,6-methoxy migration experienced with DAST for one derivative. The two reagents gave comparable yields in the fluorination of other methyl pyranosides, confirming Deoxo-Fluor as a safer alternative to DAST. Methyl α-D-mannopyranoside underwent fluorination to yield the 4,6-difluorotalopyranoside and the corresponding cyclic sulfite. The NMR spectroscopic properties of 11 benzoyl deoxy-fluoropyranosides are reported.

Keywords:

• Deoxyfluorosugars
• Diethylaminosulfur trifluoride
• Bis-(2-methoxyethyl) aminosulfur trifluoride
• DAST
• Deoxo-Fluor
• Benzoyl pyranosides
• ¹⁹F NMR

ACKNOWLEDGMENTS

NTNU is acknowledged for use of NMR facilities, Anders Jahres Foundation for financial support, and Anders Brunsvik for HRMS.