Synthesis and molecular structure of methyl 4,6-benzylidene-3-deoxy-3-diphenylarsino-α-D-altropyranoside

Abstract

The synthesis, NMR spectra (solution 1H and 13C, and solid-state 13C) and the crystal structure of methyl 4,6-O-benzylidene-3-deoxy-3-diphenylarsino-α-D-altropyranoside ( I) are reported. Air-stable I was obtained by reaction of Ph 2 AsLi with either methyl 2,3-anhydro-4, 6- O benzylidene-α-D-mannopyranoside or methyl 4, 6- O-benzylidene-2- O- p-toluenesulphonyl- α-D-glucopyranoside. In both the solid state and in solution, the pyranose ring in compound I adopts a 4C 1 conformation. The geometry about the arsenic atom is pyramidal, with the CAsC valency angles between 97.7(2)° and 100.72(2)°, and the CAs bond lengths in the range 1.965(6)–2.003(6) Å.