NEIGHBOURING-GROUP EFFECTS IN CHEMISTRY OF 3,4-ANHYDRO-D-ALTRITOL

3,4-Anhydro-d-altritol has been prepared by the partial, acidic hydrolysis of its 1,2:5,6-di-O-isopropylidene derivative. When treated with 2.5n sodium hydroxide, 3,4-anhydro-d-altritol yields 1,4-anhydro-d-altritol and 1,5-anhydro-l-glucitol as the sole products; 2,3-anhydro-d-iditol is postulated as an intermediate. 2,3-Anhydro-1,6-di-O-triphenylmethyl-d-iditol, prepared by epoxide migration of 3,4-anhydro-1,6-di-O-triphenylmethyl-d-altritol, yields, 1,4-anhydro-d-altritol and 1,5-anhydro-l-glucitol on acidic hydrolysis. Anhydrohexitols are minor products in the hydrolysis of 3,4-anhydro-d-altritol by 0.1n sulphuric acid. Neighbouring acetoxyl-group participation is evident during the acidic hydrolysis of 1,2,5,6-tetra-O-acetyl-3,4-anhydro-d-altritol. © 1969.