L,4:3,6-dianhydrohexitols

Since no other stereoisomer but that of iditol, mannitol or sorbitol can exist in the as-fused ring series of l,4 3,6-dianhydrohexitols and since amination experiments on the ditosyl derivatives of each isomer have given three different amino derivatives, it is reasonable to assume that the two diamines which have been isolated are of the same configuration as their parent dianhydrohexitols. These two diamines LXXIV and LXXV on treatment with nitrous acid suffered deamination as expected but instead of obtaining in one case isomannide and in the other isosorbide, only one dianhydrohexitol was isolated and that was dian-hydro-L-iditol. The deamination must of course lead to the transitory carbonium cation LXXVIII and this on hydroxylation can take on any of the configurations, L-iditol, D-mannitol or D-sorbitol. That it preferentially takes on the configuration of L-iditol indicates that this is in some ways a more stable structure than the others. This behavior is paralleled... 

The acetates of the l,4 3,6-dianhydrohexitols may also be useful as plasticizers both 2,5-diacetyl-l,4 3,6-dianhydro-D-mannitol and the analogous D-sorbitol derivative have been described.97... 

Keywords a,co-Alkanediamines, l,4 3,6-Dianhydrohexitols, Aldaric acids, Aldo-nolactones, Aminoalditols, o-Glucitol, Diaminoalditols, D-Mannitol, D-Xyhtol application, Erythritols, Isoidide, Isomannide, Isosorbide, L-Arabinitol, Lipase-catalysis, Polyamides, Polycarbonates, Polyesteramides, Polyesters, Polyethers, Polyureas, Polyurethanes, Super-acid, Tartaric acids... 

Stoicheiometric RuOyCCl was also used to oxidise several furanoses, partially acylated glycosides and l,4 3,6-dianhydrohexitols [317] pyranosides to pyrano-siduloses [313] methyl 2,3,6-tri-O-benzoyl-a-D-glucopyranoside and its C-4 epimer to the a-D-xy/o-hexapyranosid-4-ulose (Table 2.3) [317], and methyl 2,3,6-trideoxy-a-D-e 7f/tro-hexapyranoside to the -a-D-,g/yceri9-hexa-pyranosid-4-ulose, an intermediate in the synthesis of forosamine [318], It was also used to oxidise benzyl 6-deoxy-2,3-0-isopropylidene-a-L-mannopyranoside to the a-L-/yxo-hexapyranosid-4-ulose [319] and for oxidation of isolated secondary alcohol functions, e.g. in the conversion of l,6-anhydro-2,3-0-isopropylidene-P-D-man-nopyranose to the-P-D-/yxo-hexa-pyranos-4-ulose mannopyranose (Fig. 2.16, Table 2.3 [20, 320, 324]). 

Circular dichroism of the nitrato (ONO) chromophore of the mono- and di-nitric esters of l,4 3,6-dianhydrohexitols was found to consist of two dichroic bands, one weak and positive, at about 265 nm, and a stronger band at —228 nm, which was positive for the endo-(R)-nitrato chromophore and negative for the exo-(S)-nitrato group.68 However, for l,4 3,6-dianhydro-D-glucitol dinitrate, which has both an endo and an exo nitrato group, both bands were positive, but [ ]ma r (+ 7,260) for the band at 225 nm was about half of the algebraic sum of this band for the di-endo (+ 18,400) and di-exo (—4,460) compounds. 

The three l,4 3,6-dianhydrohexitols show the shielding effect of the cts-fused oxolane ring on their di-O-sulfonyl derivatives. As C-2 and C-5 of 1,4 3,6-dianhydro-D-mannitol 2,5-di-p-toluene-sulfonate and 2,5-dimethanesulfonate are open to attack from the exo direction, they react readily with such nucleophilic reagents as benzoate in /V,iV-dimethylfoimainide,94 acetate in acetone,93 thioacetate,95 phthalimide in A/,JV-dimethylformamide,93 and iodide in acetic anhy-dride.59<6) Inversion occurs at these positions and the L-iditol configuration results, as pointed out in the several examples in Table V. However, hydroxide ion may merely saponify,92 with retention of configuration.93... 

Dinitrates of l,4 3,6-dianhydrohexitols have been prepared by Formann, Carr and Krantz [29] in an attempt to obtain vasodilatory substances. Jackson and Hayward [30] studied their chemical properties. 

Isosorbide, an l,4 3,6-dianhydrohexitol, is readily obtained from the double dehydration of sorbitol. Amongst other chemical derivatives, diesters and diethers of sorbitol have already found application as solvents or plasticizers. Functionalization of the two alcohols groups attached to the rather rigid V-shaped framework of the two... 

Lai J, Bigot S, Sauthier M, Molinier V, Suisse I, Castanet Y, Aubry J-M, Mortreux A (2011) Telomerisation of 1,3-butadiene with l,4 3,6-dianhydrohexitols an atom-economic and selective synthesis of amphiphilic monoethers from agro-based diols. ChemSusChem 4 1104-1111... 

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