Isohexide esters

The infrared spectra (benzene solution) of the isohexide nitrates, as well as of their mixed nitric and p-toluenesulfonic esters, are well established. The positions of the v and the bands for the nitrato group are remarkably constant, at 1645 3 cm-1 and 1282 1 -1 (endo), and 1274 1 cm-1... 

Some special esters of isohexides (prepared conventionally, however) have been described, including diesters of several long-chain fatty acids121,122 and dicarboxylic acids,123 isomannide-mono-oleate,124 isosorbide dinicotin-ate,125 and perfluorinated long-chain fatty acid diesters of isosorbide and isomannide.126 Bis(chloroformate)s of isosorbide and isomannide, and the... 

Epoxides 72 may also act as starting materials for hybrid structures 77 containing an isohexide and a glyceryl moiety, with nitric ester functions at different positions.172 Additional monoethers of isosorbide 2- and 5-nitrate 78 were synthesized by reaction of the free hydroxyl group with any of several alkyl iodides in the presence of freshly prepared silver oxide. The yields were low, as usual.146 Amongst a larger series of different alcohol... 

Mesylates and tosylates of isosorbide and isomannide undergo nucleophilic displacement with a number of primary and secondary amines, as described in a pharmaceutically oriented publication.131 Several patents describe the preparation of numerous aminodeoxyisohexide derivatives bearing an additional nitric ester group at the 2 or 5 position of the isohexide ring-system.142 144 207 Among these, purines and purine-alkylamines were... 

Because of the known vasodilating activity of isohexide nitric esters, several attempts were made to improve or modify these compounds by introducing additional substituents at the second hydroxyl group. On the one hand, this type of molecular modification would influence the polarity and... 

Nicotinic esters (R = 3-pyridylcarbonyl, 78e), 4-chlorophenyl ethers (R = 4-Cl-CfiH4, 78f), and mesylates (R = S02CH3, 78g) of all three epi-meric isohexides have been the subject of a patent application.147... 

Isosorbide mono(tetradecanoate) (I66d) prevents the denaturation of ground fish during freezing.245 Mixed ether-ester-substituted isohexides (especially those of isosorbide) are used as flavor enhancers.246... 

Storbeck and Ballauff were the first to report on polyesters based on FDCA and dianhydro-hexitols [16]. Here, the acid chloride of FDCA was reacted with all three dianhydrohexitol isomers, in 1,1,2,2-tetrachloroethane in the presence of pyridine, giving white, fibrous polyesters. This work has been discussed in detail in the preceding section on isohexide polyesters (section 9.2.2). Later, Gandini and co-workers performed some kinetic studies on the transesterification of the FDCA dimethyl ester [66-68]. However, little attention was paid to polymer properties. More recently a series of papers on FDCA polyesters has been published by various groups, indicating the renewed interest in this subject. 

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