Epoxide migration and pseudo-epoxide migration of 1,6:2,3- and 1,6:3,4-dianhydro-ß-D-hexopyranoses. Synthesis of some deoxy halo derivativess of 1,6-anhydro-ß-D-hexopyranoses
2006
Abstract
Epoxide or pseudo-epoxide migration of 1,6:2,3-dianhydro- and 1,6:3,4-dianhydro-ß-D-hexopyranoses was effected by treatment with aqueous sodium hydroxide or sodium iodide in acetone to give equilibrium mixtures. Various iodo derivatives of 1,6-anhydro-ß-D-hexopyranoses were prepared as potential intermediates for pseudo-epoxide migration.
NMR was used for following the reaction mechanism of epoxide and pseudo-epoxide migrations and analysis of reaction mixtures. Experimental data were compared with DFT calculations.
Chair - boat equilibration of 1,6-anhydro-3-deoxy-3-halo-ß-D-glucopyranoses was discussed.