Developing an asymmetric, stereodivergent route to selected 6-deoxy-6-fluoro-hexoses

作者:Caravano Audrey; Field Robert A; Percy Jonathan M*; Rinaudo Giuseppe; Roig Ricard; Singh Kuldip
来源:Organic and Biomolecular Chemistry, 2009, 7(5): 996-1008.
DOI:10.1039/b815342f

摘要

Free radical bromination and nucleophilic fluorination allows the conversion of methyl sorbate into the 6-fluoro analogue which undergoes sequential asymmetric dihydroxylation reactions. A range of 6-deoxy-6-fluorosugars were prepared by using different combinations of ligands. While the enantiomeric excesses obtained were comparable to those from other 6-substituted sorbates, the regioselectivity of dihydroxylation was moderate, with both 2,3-and 4,5-diols being obtained. A successful temporary persilylation strategy was evolved to convert the products of dihydroxylation rapidly to the fluorosugars 6-deoxy-6-fluoro-L-idose, 6-fluoro-L-fucose and 6-deoxy-6-fluoro-D-galactose, which were obtained in overall yields of 4%, 6% and 8% from methyl 6-fluoro-hexa-2E, 4E-dienoate 6.

  • 出版日期2009