Synthesis, and x-ray structural analysis, of 1,2,3,4-tetra-O-acetyl-5,6-dideoxy-5-C-[(S)-phenylphosphinyl]-α- and -β-l-idopyranose

The title compounds and two diastereoisomers were prepared from (5 RS )-3- O -benzyl-5,6-dideoxy-5- C -[( RS )-(ethoxy)phenylphosphinyl]-1,2- O -isopropylidene-α- d - xylo -hexofuranoses upon reduction with sodium dihydrobis(2-methoxyethoxy)-aluminate, followed by hydrolysis with mineral acid, and acetylation with acetic anhydride-pyridine. Among these products, the two readily crystallized compounds were determined by X-ray crystallographic analysis to be 1,2,3,4-tetra- O -acetyl-5,6-dideoxy-5- C -[( S )-phenylphosphinyl]-α- and -β- l -idopyranose- 4 C 1 .