1,4-anhydride formation of solvolysis of 1,6-disubstituted derivatives of 2,3,4,5-tetra-O-acetylallitol

The 6-O-mesyl, 6-O-tosyl, 6-bromo-6-deoxy, and 6-deoxy-6-iodo derivatives of 1,4-anhydro-DL-allitol were obtained by treatment of the corresponding 1,6-di-substituted derivatives (2, 3, 6, 4) of 2,3,4,5-tetra-O-acetylallitol with hot, methanolic hydrogen chloride. Compounds 2 and 3 were prepared by the acetolysis of the 1,6-di-O-mesyl and 1,6-di-O-tosyl derivatives (8 and 11) of di-O-benzylideneallitol. Iodide displacement on 2 gave 4, and detritylation-bromination of 2,3,4,5-tetra-O-acetyl-1,6-di-O-tritylallitol (5) gave 6. The acetal residues of di-O-benzylideneallitol have been shown to span the secondary carbon atoms.