IN an exhaustive study of the action of hydrochloric acid on mannitol, Montgomery and Wiggins1 isolated no fewer than four dianhydrohexitols from this reaction. These compounds were : (a) 1 : 4-3 : 6-dianhydromannitol (isomannide); (b) 1 : 5-3 : 6-dianhydromannitol (neomannide); (c) dianhydrohexitol (A), m.p. 118°, [α]D – 34°; and dianhydrohexitol (B), isolated only as its dimethanesulphonate, m.p
Viehe's salt allows the transformation of unprotected hexitols and pentitols into linear 1,6 and 1,5 dichloro derivatives in high yields. Usual competitive heterocyclization is minimized.
Micheel, Justus Liebigs Annalen der Chemie, 1932, vol. 496, p. 77,92