Alditol Anhydrides. Elsevier; 1970. pp. 229-83. [DOI: 10.1016/s0065-2318(08)60429-1]

Green recyclable SO3H-carbon catalyst for the selective synthesis of isomannide-based fatty acid monoesters as non-ionic bio-surfactants

Solvent free one-pot synthesis of isomannide-based fatty acid monoesters as non-ionic bio-surfactants employing a green recyclable SO₃H-carbon catalyst was demonstrated.

Synthesis and structure of selected quaternary N-(1,4-anhydro-5-deoxy-2,3-O-isopropylidene-D,L-ribitol-5-yl)ammonium salts

The syntheses have been developed for quaternary N-(1,4-anhydro-5-deoxy-2,3-O-isopropylidene-D,L-ribitol-5-yl)ammonium salts derived from five aromatic amines, pyridine, 2-methylpyridine, 3-carbamoylpyridine, 4-(N,N-dimethylamino)pyridine, and quinoline, as well as two tertiary aliphatic amines, trimethylamine and triethylamine. Reactions of 1,4-anhydro-2,3-O-isopropylidene-5-O-tosyl-D,L-ribitol with tri-n-propylamine and tri-n-butylamine were unsuccessful. The products were identified on the basis of their 1H and 13C NMR spectra. The structure of N-(1,4-anhydro-5-deoxy-2,3-O-isopropylidene-D,L-ribitol-5-yl)trimethylammonium tosylate was additionally elucidated by X-ray diffractometry.

Glycosylation of l,4:3,6-dianhydro-d-glucitol (isosorbide)

Condensation of 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl-, 2,3,4-tri-O-acetyl-alpha-D-xylopyranosyl- and of 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromides with l,4:3,6-dianhydro-D-glucitol under Koenigs-Knorr conditions, and using the Helferich modification of the reaction showed regioselectivity in glysosylation at C-5 of isosorbide.

Separation and characterization of adjuvant oligosaccharide oleate ester derived from product mixture of mannitol-oleic acid esterification

Nearly 30 years after intense investigations of mannide monooleates for use as vaccine adjuvants, a novel adjuvant-active saccharide oleate ester was isolated and identified from the product mixture synthesized from mannitol and oleic acid. The mixture, which contained many kinds of mannide mono- and dioleates and their derivatives, was fractionated by liquid chromatography (LC), and the fraction with the highest adjuvanticity was obtained. Gel permeation chromatography (GPC) showed that it consisted of one major compound with an average molecular weight (MW) 2850. Infrared (IR) absorption and proton nuclear magnetic resonance spectra suggested it had oligosaccharide moieties and oleate domains. These findings suggested that it was an oligosaccharide oleate ester of the average MW 2850. The molecular ratio of oleate chains per monosaccharide unit was approximately 0.8. The ester induced both IgG1 and IgG2a antibody responses in mice in a dispersed form without base oil. This ester thus appears to be one of the adjuvant-active compounds largely contributing to the excellent adjuvanticity of mannide oleate mixture broadly used as vaccine emulsifier. These results and previous findings suggest that the fundamental adjuvanticity of this 'oligo' saccharide acylate ester was in accord with the hydrophil-lipophil balance (HLB) theory, similarly to other saccharide acylate esters. It is now expected that this compound will be useful as novel vaccine adjuvant which may induce both Th1 and Th2 type immune responses with low or no toxicity, not only as an vaccine emulsifier but in an aqueous suspension form.

The solvent-free thermal dehydration of hexitols on zeolites

Dehydration of galactitol, D-glucitol and D-mannitol at high temperature in the presence of molecular sieves without solvent under an argon atmosphere is described. Cyclodehydration products with retention or inversion of the configuration at asymmetric carbon atoms, were observed. Reaction of galactitol yielded racemic 1,4-anhydrogalactitol in a first step and then racemic 1,4:3,6-dianhydroiditol. Complete analytical separations of exhaustively O-acetylated reaction products were achieved by GC and structures were assigned using co-injection with standards.

1,5-Anhydro-D-fructose; a versatile chiral building block: biochemistry and chemistry

There is a steadily increasing need to expand sustainable resources, and carbohydrates are anticipated to play an important role in this respect, both for bulk and fine chemical preparation. The enzyme alpha-(1-->4)-glucan lyase degrades starch to 1,5-anhydro-D-fructose. This compound, which has three different functional properties, a prochiral center together with a permanent pyran ring, renders it a potential chiral building block for the synthesis of valuable and potentially biologically active compounds. 1,5-Anhydro-D-fructose is found in natural materials as a degradation product of alpha-(1-->4)-glucans. The occurrence of lyases and the metabolism of 1,5-anhydro-D-fructose are reviewed in the biological part of this article. In the chemical part, the elucidated structure of 1,5-anhydro-D-fructose will be presented together with simple stereoselective conversions into hydroxy/amino 1,5-anhydro hexitols and a nojirimycin analogue. Synthesis of 6-O-acylated derivatives of 1,5-anhydro-D-fructose substituted with long fatty acid residues is carried out using commercially available enzymes. Those reactions lead to compounds with potential emulsifying properties. The use of protected derivatives of 1,5-anhydro-D-fructose for the synthesis of natural products is likewise reviewed. The potential utilization of this chemical building block is far from being exhausted. Since 1,5-anhydro-D-fructose now is accessible in larger amounts through a simple-enzyme catalyzed degradation of starch by alpha-(1-->4)-glucan lyase, the application of 1,5-anhydro-D-fructose may be considered a valuable contribution to the utilization of carbohydrates as the most abundant resource of sustainable raw materials.