Azomethine ylide cycloaddition of 2-C-formyl glycals with α-amino acids for the synthesis of substituted pyrroles
作者:V. Veerabadhra Reddy、B.V. Subba Reddy
DOI:10.1016/j.tet.2021.132389
日期:2021.9
for the synthesis of pyrrole based acyclo-C-nucleosides, in particular an open-chain sugar substituted pyrrole derivatives by means of the condensation of 2-C-formyl glycals with α-aminoacids through an intramolecular azomethine cycloaddition under thermal conditions. The use of cyclic α-aminoacids provides the corresponding bicyclic pyrrole derivatives. This is a first report on the synthesis of pyrrole
We report the use of XtalFluor-E ([Et2NSF2]BF4) as an alternative to POCl3 in the Vilsmeier–Haack formylation reaction of C-2-glycals. Employing a XtalFluor-E/DMF combination allowed the desired C-2-formyl glycals to be isolated in 11–90% yield. This method was extended to the synthesis of a C-2-formylated disaccharide glycal.