REINVESTIGATION OF THE ACETALATION OF D-GLUCITOL WITH ACETONE-ZINC CHLORIDE

Article abstract of DOI:10.1016/S0008-6215(00)83836-7

The acetonation of D-glucitol in the presence of zinc chloride has been studied in detail by gas-liquid chromatographic techniques.From among the 12 different peaks, those belonging to the 1,2:3,4:5,6-tri-, 1,2:3,5:4,6-tri-, 3,4:5,6-di-, 2,3:5,6-di-, 1,2:3,4-di-, 1,2:5,6-di-, 1,2:4,6-di-, 1,2-mono-, 2,3-mono-, 3,4-mono-, and 5,6-mono-acetals could be identified.The course of the reaction was also studied by g.l.c.From the time dependent ratio of the different acetals, it could be concluded that the reaction is kinetically controlled at the beginning, when terminal acetals are mainly formed.In the thermodinamically controlled equilibrium, reached after 5 days, the 1,2:3,4:5,6-tri- and the 2,3:5,6-di-acetal are present in almost equal proportions.The structure of the (new) 1,2:3,5:4,6-triacetal was established by mass-spectrometric and 13C-n.m.r. investigation.