Acyclic C-nucleosides: Synthesis of chiral 1,1-diheteroaryl-alditols and X-ray crystal structure of 2,3,5-tri-O-benzyl-1,1-di-(2'-pyrryl)-1-deoxyl-D-arabinitol

Tetra-O-acetyl-D-ribose, penta-O-acetyl-D-glucose, 2,3;5,6-di-O-isopropylidene-D-mannofuranose, 2,3,5-tri-O-benzyl-D-arabinofuranose and 2,3,5,6-tetra-O-benzyl-D-glucose react with pyrrole and indole, in presence of Lewis acids, to afford C-glycosylpyrroles and indoles in position 2 and 3 respectively (acyclic C-nucleosides, 1-7). The crystal structure of 4 was determined by X-ray crystallography.