- METHODS OF SYNTHESIS OF SCYLLITOL AND RELATED COMPOUNDS
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Methods of synthesis of scyllitol diborate and related compounds are provided, including methods that are performed in all-aqueous solutions. Also provided are methods in which the reaction products are recycled to increase the efficiency of the process. The methods include the steps of conversion of a solution of inositol to scyllitol, conversion of scyllitol in the solution to scyllitol diborate, and isolation of the scyllitol diborate from the solution. The scyllitol diborate is reacted to form substantially pure scyllitol diborate, and the remaining solution is efficiently recycled to scyllitol diborate, then to additional substantially pure scyllitol. This scyllitol diborate recycling step can be applied to a variety of processes to improve the yield of scyllitol. The methods are highly efficient and result in large scale reaction products of high purity.
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Page/Page column 58-61
(2012/05/04)
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- Efficient syntheses of optically pure chiro- and allo-inositol derivatives, azidocyclitols and aminocyclitols from myo-inositol
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Efficient routes for the syntheses of optically pure and hitherto unknown l-chiro- and d-allo-inositol derivatives, azido- and aminocyclitols of l-chiro-configuration, diazido- and diaminocyclitols of d-allo-configuration from economically viable myo-inositol are described. These routes provide access to synthetically flexible 1,2:4,5-di-O-isopropylidene-chiro-inositol and 1,6:3,4-di-O-isopropylidene-allo-inositol, which are otherwise difficult to synthesize directly from their parent inositols. A one pot methodology that allows rapid access to both chiro- and allo-inositol derivatives has also been developed. Investigations on the glycosidase inhibitory properties of these novel azido- and amino-inositols unraveled the potentials of these classes of compounds as novel class of glycosidase inhibitors. Both d and l forms of these cyclitols could be synthesized from myo-inositol in gram scales and hence by exploiting the difference in reactivities of cis- and trans-ketals, a variety of protected derivatives, which are useful for the synthesis of unnatural phosphoinositols and natural products, can be synthesized.
- Sureshan, Kana M.,Ikeda, Kyoko,Asano, Naoki,Watanabe, Yutaka
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p. 4072 - 4080
(2008/09/20)
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- Simple and Efficient Routes to Optically Active chiro- and allo-Inositol Derivatives from myo-Inositol
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Efficient routes for the gram scale syntheses of optically active chiro- and allo-inositol derivatives from readily available 1,2:4,5-di-O- isopropylidene-myo-inositol (1) are described. Both D and L forms of these isomeric inositols could be synthesized from enantiomers of 1. One-pot methodology for the simultaneous synthesis of both chiro and allo has also been developed. The possible selectivity for the cleavage of trans-ketal in presence of the cis is an added advantage for the syntheses of a variety of protected derivatives for phosphoinositol syntheses. These routes provide synthetically flexible 1,2:4,5-di-O-isopropylidene-chiro-inositol and 1,6:3,4-di-O- isopropylidene-allo-inositol which are difficult to achieve otherwise.
- Sureshan, Kana M.,Watanabe, Yutaka
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p. 493 - 496
(2007/10/03)
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- Stereoselective synthesis of myo-, neo-, L-chiro, D-chiro, allo-, scyllo-, and epi-inositol systems via conduritols prepared from p-benzoquinone
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A practical route is described for the flexible preparation of a wide variety of inositol stereoisomers and their polyphosphates. The potential of this approach is demonstrated by the synthesis of myo-, L-chiro-, D-chiro-, epi-, scyllo-, allo-, and neo-inositol systems. Optically pure compounds in either enantiomeric form can be prepared from p-benzoquinone via enzymatic resolution of a derived conduritol B key intermediate. High-performance anion-exchange chromatography with pulsed amperometric detection permits inositol stereoisomers to be resolved and detected with high sensitivity. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Podeschwa, Michael,Plettenburg, Oliver,Vom Brocke, Jochen,Block, Oliver,Adelt, Stephan,Altenbach, Hans-Josef
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p. 1958 - 1972
(2007/10/03)
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- Stereo- and regiospecificity of yeast phytases-chemical synthesis and enzymatic conversion of the substrate analogues neo- and L-chiro-inositol hexakisphosphate
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Phytases are enzymes that catalyze the hydrolysis of phosphate esters in myo-inositol hexakisphosphate (phytic acid). The precise routes of enzymatic dephosphorylation by phytases of the yeast strains Saccharomyces cerevisiae and Pichia rhodanensis have been investigated up to the myo-inositol trisphosphate level, including the absolute configuration of the intermediates. Stereoselective assignment of the myo-inositol pentakisphosphates (D-myo-inositol 1,2,4,5,6-pentakisphosphate and D-myo-inositol 1,2,3,4,5-pentakisphosphate) generated was accomplished by a new method based on enantiospecific enzymatic conversion and HPLC analysis. Via conduritol B or E derivatives the total syntheses of two epimers of myo-inositol hexakisphosphate, neo-inositol hexakisphosphate and L-chiro-inositol hexakisphosphate were performed to examine the specificity of the yeast phytases with these substrate analogues. A comparison of kinetic data and the degradation pathways determined gave the first hints about the molecular recognition of inositol hexakisphosphates by the enzymes. Exploitation of the high stereo- and regiospecificity observed in the dephosphorylation of neo- and L-chiro-inositol hexakisphosphate made it possible to establish enzyme-assisted steps for the synthesis of D-neo-inositol 1,2,5,6-tetrakisphosphate, L-chiro-inositol 1,2,3,5,6-pentakisphosphate and L-chiro-inositol 1,2,3,6-tetrakisphosphate.
- Adelt, Stephan,Podeschwa, Michael,Dallmann, Guido,Altenbach, Hans-Josef,Vogel, Guenter
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- L-chiro-inositol derivatives from myo-inositol. Building blocks for inositolphosphoglycans
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A straightforward synthesis of L-chiro-inositol, deoxy L-chiro-inositol derivatives and L-chiro-inositol building blocks for the preparation of inositolphosphoglycans, is reported from myoinositol. Glycosylation with 2-azido-3,4,6-tri-O-benzyl-2-deoxy-D-g
- Cid, M. Belén,Alfonso, Francisco,Martín-Lomas, Manuel
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p. 1370 - 1372
(2007/10/03)
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- Novel synthesis of enantiomerically pure natural inositols and their diastereoisomers
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The various inositol polyphosphates have been found to trigger many important biological processes. Although the knowledge of this phosphoinositide signaling system has been discovered in the past 10 years, many factors remain unclear. For this reason, there is an increased demand for supplies of D-myo-inositol and particularly of novel analogues to investigate these biological mechanisms in more detail. Herein, we report the efficient syntheses of all diastereoisomers of inositol starting with 6-O-acetyl-5-enopyranosides. Conversion of 6-O-acetyl-5-enopyranosides into the corresponding substituted cyclohexanones (Ferrier-II rearrangement) was found to proceed efficiently with a catalytic amount of palladium dichloride. Stereoselective reduction of β-hydroxy ketones obtained provided the precursors to all inositol diastereoisomers in good to excellent yields and with high stereoselectivities. Good accessibility of these enantiomerically pure inositol diastereoisomers results in the efficient syntheses of D-myo-inositol 1,4,5-trisphosphate and D-myo-inositol 1,3,4,5-tetrakisphosphate.
- Takahashi,Kittaka,Ikegami
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p. 2705 - 2716
(2007/10/03)
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- New syntheses of 1D- and 1L-1,2-anhydro-myo-inositol and assessment of their glycosidase inhibitory activities
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The 1D and 1L enantiomers of 1,2-anhydro-myo-inositol (conduritol B epoxide) were synthesised from 1d-pinitol and 1l-quebrachitol, respectively, and their activities were compared in selected glycosidase inhibition assays. The 1d enantiomer was found to be the active isomer, functioning as an irreversible inhibitor of sweet almond β-D-glucosidase. Neither isomer was active against the α-D-glucosidase from Bacillus stearothermophilus or the β-D-galactosidase from Aspergillus oryzae. (C) 2000 Elsevier Science Ltd.
- Falshaw, Andrew,Hart, Joanne B.,Tyler, Peter C.
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p. 301 - 308
(2007/10/03)
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- Inositol synthesis: Concise preparation of L-chiro-inositol and muco- inositol from a common intermediate
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Fully stereoselective large-scale syntheses have been attained for L- chiro-inositol (2) and muco-inositol (3) by means of controlled peripheral oxygenation of cyclohexadiene diol 1.
- Brammer Jr., Larry E.,Hudlicky, Tomas
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p. 2011 - 2014
(2007/10/03)
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- Transformation of cyclohexene to enantiopure cyclitols mediated by sequential oxyselenenylation with (S,S)-hydrobenzoin: Synthesis of D-chiro-inositol and muco-quercitol
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Oxyselenenylation of cyclohexene with (S,S)-hydrobenzoin and subsequent oxidation-elimination allows isolation of an allylic ether in which further phenylselenenylation is completely regioselective, thus allowing entry to the cyclitols D-chiro-inositol and muco-quercitol.
- Kim, Kwan Soo,Park, Jong H.,Moon, Hoi Kyung,Yi, Hann
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p. 1945 - 1946
(2007/10/03)
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- Synthesis of L-chiro-inositol and (-)-conduritol F from D-sorbitol by a highly stereoselective intramolecular pinacol coupling promoted by samarium diiodide
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A synthesis of L-chiro-inositol and (-)-conduritol F starting from readily available D-sorbitol is described. The route involves as a key step an efficient one-pot sequence consisting of the Swern oxidation of a 1,6-diol followed by a highly stereoselecti
- Chiara,Valle
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p. 1895 - 1898
(2007/10/03)
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- Microbial Oxidation of Aromatics in Enantiocontrolled Synthesis. Part 1.Expedient and General Asymmetric Synthesis of Inositols and Carbohydrates via and Unusual Oxidation of a Polarized Diene with Potassium Permanganate
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This paper reports on the details of a general design of carbohydrates and cyclitols from biocatalytically derived synthons.Homochiral 1-halogenocyclohexa-4,6-diene-2,3-diols 1a and 1b have been generated from chloro- and bromobenzene, respectively, by means of bacterial dioxygenase of Pseudomonas putida 39D.These chiral synthons have been manipulated to cyclitols and carbohydrates by further stereoselective functionalizations.The preperation of D-chiro-inositol, neo-inositol, muco-inositol, and allo-inositol exemplifies their use in enantiocontrolled synthesis.A novel oxidation of polarized dienes with KMnO4 resulted in the synthesis of α-halogeno epoxy diols, which proved unexpectedly stable.A mechanism is proposed for this transformation and placed in context with the only four reported examples of this reaction in the literature.In addition to the application of this new chemistry to the synthesis of cyclitols, chloro epoxy diol 21a has been transformed into a series of cyclitol synthons by reductive or hydrolytic operations.Reaction of 21a with ammonia led to the preparation of highly oxygenated pyrazines, whose structure were proven by X-ray crystallography.The use of 21a in the preparation of D-chiro-3-inosose, a hitherto unreported cyclitol derivative, is also reported.In addition, chloro epoxy diol 21a was transformed into D-erythruronolactone, completing the synthesis of this important chiral pool reagent in two operations from chlorobenzene.Oxidative cleavage of tetrol 20 yielded D-mannosolactone identical with an authentic sample.
- Hudlicky, Tomas,Mandel, Martin,Rouden, Jacques,Lee, Robert S.,Bachmann, Bryan,et al.
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p. 1553 - 1568
(2007/10/02)
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- General Synthesis of Inositols by Hydrolysis of Conduritol Epoxides Obtained Biocatalytically from Halogenobenzenes: (+)-D-chiro-Inositol, allo-Inositol, muco-Inositol and neo-Inositol
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Four of the nine isomeric inositols have been prepared by hydrolytic opening of epoxides derived from 3-halogenocyclohexa-3,5-diene-1,2-diol by further oxidation with potassium permanganate or by reduction of chiro-3-inosose (2L-2,3,6/4,5-pentahydroxycyclohexanone).
- Mandel, Martin,Hudlicky, Thomas
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p. 741 - 744
(2007/10/02)
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- Synthesis from quebrachitol of 1L-chiro-inositol 2,3,5-trisphosphate, an inhibitor of the enzymes of 1D-myo-inositol 1,4,5-trisphosphate metabolism
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L-Quebrachitol was O-demethylated to give 1L-chiro-inositol which, on treatment with dibutyltin oxide, benzyl chloride, and tetrabutylammonium iodide in acetonitrile, gave mainly crystalline 1L-2,3,5-tri-O-benzyl-chiro-inositol (5a) together with 1L-2,3,5
- Liu,Nahorski,Potter
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p. 107 - 115
(2007/10/02)
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- GLYCOSYL-INOSITOL DERIVATIVES III. SYNTHESIS OF HEXOSAMINE-INOSITOL-PHOSPHATES RELATED TO PUTATIVE INSULIN MEDIATORS
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The disaccharides related to glycosyl phosphatidyl inositol anchors of membrane proteins, 4-O-(2-amino-2-deoxy-α-D-glucopyranosyl)-D-myo-inositol-1-phosphate and 4-O-(2-amino-2-deoxy-α-D-galactopyranosyl)-D-chiro-inositol-1-phosphate, have been prepared from optically resolved myo-inositol derivatives.The chiro-inositol moiety was obtained by epimerization of a selectively blocked myo-inositol-triflate ester.The resolved inositols were subsequently phosphorylated to yield the disaccharide aglycones.The amino-sugar components were prepared by azidonitration of suitably protected glucal and galactal derivatives.The derived pyranosyl chlorides were then condensed with the inositol phosphates using silver triflate as the promoter.
- Berlin, William K.,Zhang, Wen-Sheng,Shen, T. Y.
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- NOVEL BIOSYNTHESIS OF D-PINITOL IN SIMMONDSIA CHINENSIS
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Chase experiments with 14CO2 and feeding experiments with labwelled inositols showed that D-pinitol in leaves of Simmondsia chinensis arises via epimerization of D-ononitol.This finding represents an alternative pathway, since D-pinitol is formed in gymnosperms and other plants by epimerization of sequoyitol.Key Word Index -- Simmondsia chinensis; Simmondsiaceae; jojoba; biosynthesis; cyclitols; D-pinitol; D-ononitol.
- Dittrich, Peter,Korak, Andrea
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- PURIFICATION AND STRUCTURE DETERMINATION OF THREE α-D-GALACTOPYRANOSYLCYCLITOLS FROM SOYA BEAN
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Three α-D-galactopyranosylcyclitols previously isolated from soya bean are shown to be 1D-2-O-(α-D-galactopyranosyl)-4-O-methyl-chiro-inositol, 1D-5-O-(α-D-galactopyranosyl)-4-O-methyl-chiro-inositol, and 1D-2-O-(α-D-galactopyranosyl)-chiro-inositol.Assignments of the (13)C-n.m.r. spectra of these compounds and of 1L-1-O-(α-D-galactopyranosyl)-myo-inositol (galactinol) are presented.The mass spectra of derivatives prepared by permethylation or perdeuteriomethylation, followed by hydrolysis and acetylation or methylation are discussed.
- Schweizer, Thomas F.,Horman, Ian
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