Trehalose derivative

Comparison of Sweetness between Trehalose Derivatives and the Corresponding Monosaccharide Analogs by Paired Comparison Test d... 

SCHEME 33. Fluoro-trehalose derivatives prepared by Hough, Richardson, and Hadfield (1978). 

The selective removal of one of two acetal groups that are symmetrically disposed within a diacetal may be achieved. l,3 2,4-Di-0-ben-zylidene derivatives of erythritol and L-threitol have been converted41 into their 1,3-acetals, and selective methanolysis of 2,3,2, 3 -tetra-0-benzoyl-4,6 4, 6 -di-0-benzylidene-a,a-trehalose gave42 the mono-benzylidene derivative in 47% yield, thereby offering a route to un-symmetrically substituted a,a-trehalose derivatives. 

Disaccharides to have been examined are two D-ribofuranosyl-D-ribitols produced from two bacterial capsular polysaccharides, and several aa-trehalose derivatives prepared as model bacterial cord factors [F.D. cationization with cesium iodide gave intense (M + Cs) ions]. The same group of workers have also reported on this method applied to the natural cord factor of Corynebacterium diphtheriae, and they found at least 22 species differing in the chain lengths of the two trehalose acyl substituents. A further report describes the determination of the sites of substitution of the acyl groups.Daunosamine-containing disaccharides have been examined by negative ion, positive ion, chemical ionization, and electron-impact methods. 

Enzymic methods were used to link a-D-glucopyranose to the anomeric positions of a-D-lyxopyranose and P-D-xylulose. Various dichloro-dideoxy sucroses and products derived by selective nucleophilic displacement of single chlorine atoms are referred to in Chapter 8. Trehalose derivatives carrying long-chain branched fatty acid residues are referred to in Chapter 19. 

Brown JM, Cook SJ (1986) Hydroformylation catalysed by rhodium complexes of trehalose-derived ligands aa and PP-TREDIP a highly regioselective route to a-Methylarylpropionaldehydes. Tetrahedron 42 5105-5109... 

Tuberculosis still remains a major health problem in the world, with almost 1.5 million deaths annually. Sulfoglycolipids were identified as new mycobacterium antigens able to control mycobacterial infection" and appeared to be promising additive candidates for the development of a new tuberculosis vaccine. These complex metabolites are acylated and sulfated a,a-D-trehalose derivatives which are found in the cell wall of Mycobacterium tuberculosis (Scheme 16)." Efficient access to di-O- and tetra-O-acylated sulfoglycolipid analogues have been developed by using the iron(iii) chloride-catalyzed tandem protocol for the functionalization of C2 symmetric a,a-D-trehalose. ... 

A full account has been given of the work by Brimacombe s group (see Vol. 23, p. 9) on the formation of octuronic acid derivatives by catalytic osmylation of a,p-unsaturated esters in the presence of Sharpless chiral ligands, where double asymmetric induction can be used to enhance the Kishi selectivity.66 The trehalose derivative (44) could be homologated to the bis-uronic acid (45) using a carbonyl insertion procedure (Scheme 13), as well as by use of the reaction of cyanide ion on the ditriflate analogous to (44)67... 

Other references to aldosuloses and dialdoses can be found in the following chapters the synthesis of 6-acetamido-6-deoxy-D-Jcy/o-hexos-5-ulose (Chapter 8) the formation of heterocyclic derivatives from dialdoses (Chapter 10) the reactions of dialdoses with Wittig reagents (Chapter 3) and Ivanov s reagent (Chapter 17) the base-catalysed cyclization of D-jcy/o-hexos-5-ulose 6-phosphate (Chapter 19) the oxidation of oca-trehalose derivatives to glycosiduloses (Chapter 22). 

Diazido-4,4 -dideoxy-ga/acto-trehalose was synthesized from a known partially benzoylated trehalose derivative by formation and azide ion displacement of a 4,4 -ditriflate, and was claimed to have antimicrobial properties. ... 

The trehalose derivatives 3-0-benzyl-4,6-0-benzylidene-2-deoxy-a-D-ri/>o-hexopyranosyl 4, 6 -0-benzylidene-2 -deoxy-a-D-rifto-hexopyranoside and 2,2, 3,3 -tetra-0-benzoyl-6,6 -dideoxy-4,4 -di-0-mesyl-6,6 -dithiocyanato-a,o-tre-halose di-iV-acetylchitobiose complexed to turkey egg lysozyme. ... 

The H- and C-n.m.r. spectra of sucrose, methyl a-D-fructofuranoside (20) and methyl P D-fhictofuranoside (21) with single sites of C-substitution at C-1, C-2, C-3-, or C-6 of the furanose moieties have been analysed to assess the conformations of the their furanose rings, and of the glycosidic linkages in aqueous solution. In addition, spin-couplings in 20 and 21 were compared with those of a-(22) and p-D-r/jrco-pentulofuranose (23), respectively, to study the effect of glycosidation and hydroxymethyl substitution on the solution conformations. The conformations of 2-mono- and 2,2 -di-G-substituted a,a-trehalose derivatives 25 have been shown by n.m.r. spectroscopy in combination with molecular mechanics calculations, to differ from that of the 2,2 -unsubstituted disaccharide 24, both in solution and in the solid state. N.O.e. experiments on the 6 -deoxy-, 6 -thio-, and 6 -0-THP derivatives of methyl 2-acetamido-2-deoxy-P-lactoside, potential inhibitors of (2- 6)-a-sialyltransferase, proved that they adopt the same conformation as the parent compound. ... 

Srinivasachari et al. utilized the click reaction between a diazido-trehalose derivative and dipropargyl amide of oligoethyleneimine (Scheme 7.7) [11] the use of the CuAAC reaction enabled them to prepare polymers of significantly... 

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