Preparation of 5-telluropentopyranose sugars from common pentose starting materials

2,3,4-Tri-O-benzyl-1,5-dideoxy-5-telluro-d-arabinose (5) and 2,3,4-tri-O-benzyl-1,5-dideoxy-5-telluro-l-arabinose (7) are readily prepared by treatment of d- and l-2,3,4-tri-O-benzyl-1,5-di-O-methanesulfonylarabitol with sodium telluride (Na2Te) in ethanol.