FORMATION OF EPOXIDES FROM SUBSTITUTED HEXITOLS

1,6-Dibromo-1,6-dideoxygalactitol (2), 1-O-methanesulphonyl-D-mannitol (5), and 3,4-di-O-methanesulphonyl-D-mannitol (8) were respectively converted at nearly neutral pH into 1,2:5,6-dianhydrogalactitol (4), 1,2-anhydro-D-mannitol (6), and 2,3:4,5-dianhydro-D-iditol (9). Strongly alkaline conditions yielded 2,3:4,5-dianhydro-L-iditol (7) from 1,6-di-O-methanesulphonyl-D-mannitol (1). The structures of compounds 4, 6, 7, and 9 were confirmed by p.m.r. spectroscopy, and by their reactivity towards thiosulphate and iodide ions. The conversion of 1,2:5,6-dianhydro-D-mannitol (3) into 1,6-dideoxy-1,6-diiodo-D-mannitol, 1,6-dibromo-1,6-dideoxy-D-mannitol, and 1,6-di-O-benzoyl-D-mannitol, and 1,2:5,6-dianhydrogalactitol into 1,6-dideoxy-1,6-diiodogalactitol is described. © 1969.