Synthesis and structural studies of some cyclic acetals of hexitols

This thesis contains an account of the synthesis, and the structural studies, of some cyclic acetals of hexitols. 2,4-0-Furfurylidene-ii-glucitol, two di-O-furfurylidene-D-glucitols, and three tri-O-furfurylidene-h-glucitols have been isolated, of which the 2,4-mono-acetal and possibly one of the diacetals and one of the triacetals were previously known. The previously unknown butylidene acetals, 2,4-0-butylidene-D-glucitol,3,4-0-butylidene-D-glucitol, and 1,3:2,4-di-O-butylidene-b-glucitol, have been isolated, together with syrupy di-O-butylidene- and tri-O-butylidene-D-glucitols of unknown composition. 2,4-0-lsobutylidene-D-glucitol and a syrupy tri-O-isobutylidene-h-glucitol have also been prepared by similar methods.All the crystalline compounds have been characterised and systematic structural studies have been made upon them, The structures of the 2,4 monoacetals have been established, and the structure of the crystalline dl-O-butylidene-D-glucitol has been indicatedby partial hydrolysis, after it had been established that it was a 1,2,3,4 diacetal.Kinetic studies have been made on the hydrolysis of various monoacetals of D-glucitol in hydrochloric acid of varying strength. It has been shown that the stabilities of the 2,4-, 3,4-, and 4,6-O-butylidene-D-glucitols do not differ significantly from one another. It has also been shown that these three monoacetals, and possibly further cyclic acetals, exist in equilibrium with each other in aqueous hydrochloric acid. The Arrhenius energies of activation and frequency factors have been determined for2,4-0-butylidene-D-glucitol and 2,4-0-isobutylidene-D-glucitol, in N and 2N hydrochloric acid.Various polymeric materials have been obtained from the reaction of acrolein with a number of different polyhydroxy compounds.