The Synthesis of (R)-2',3'-Dihydroxypropyl 5-Deoxy-5-Dimethylarsinyl-β-D-Riboside, a Naturally Occurring Arsenic-Containing Carbohydrate

Abstract

The synthesis of the title compound, isolated from the brown kelp ( Ecklonia radiata ) or the giant clam (Tridacna maxima), is reported. Glycosidation of 1-O-acetyl-2,3,5-tri- O- benzoyl -β-D-ribose, either directly with (S)-1,2-di-O-benzylglycerol or via the derived orthoester with (S)-1,2-O-isopropylideneglycerol, led to two fully protected glycerol β-D- ribofuranosides. Subsequent chemical manipulations led to a common intermediate having a free hydroxy group at C5 of the D-ribose residue. Replacement of this hydroxy group by a chlorine atom allowed the introduction of the dimethylarsinyl group at C5 in a two-step procedure, and removal of protecting groups provided the natural product.