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Publisher Summary This chapter provides an overview of 1,4:3,6-dianhydrohexitol compounds. In 1884, 1,4:3,6-dianhydro- D -mannitol was described as the first member of the 1,4:3,6-dianhydrohexitols series. The 1,4:3,6-dianhydrohexitols belong to the so-called “biomass-derived substances” obtainable from natural products, and are thus classified as “regenerable resources.” Because of the lack of a chromophoric group, normal isohexides do not exhibit characteristic absorption bands in the ultraviolet region. Except for chromophoric substituents, only for the monoketones having the carbonyl group in the 2-position and the diketone( both derived from isosorbide), an absorption band is observed at 267 nm (in water). Isohexide mononitrates, as well as dinitrates, show a weak, positive dichroic band at 265 nm and a second, stronger one near 228 nm, which is positive for endo-R-nitrato and negative for em-S-nitrato groups. For isosorbide dinitrate, both dichroic bands are positive. This chapter provides details on the nomenclature of bridged systems and fused systems. It also discusses spectroscopic properties, structural aspects, and analytical detection concepts of isohexides and explains the preparation of the parent compounds. |
