- Synthesis method of voglibose
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The invention provides a synthesis method of voglibose, and solves the technical problems that in an existing synthesis method of voglibose, raw materials are difficult to obtain, high in price, large in investment, low in yield and not suitable for industrial production. The synthesis method comprises the steps: synthesizing a compound V by taking glucose monohydrate and sodium acetate as raw materials through eleven reaction steps; and preparing a compound VIII from the compound V through an addition reaction, a ring-opening reaction and an aldol condensation reaction, and thus obtaining voglibose through amination reduction of the compound VIII. The synthesis method of voglibose can be widely applied to the technical field of voglibose synthesis methods.
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- Preparation method of voglibose intermediate
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The invention provides a preparation method of a voglibose key intermediate (2R,3S,4S,5S)-5-hydroxyl-2,3,4-tri(benzyloxy)-5-[(benzyloxy)-methyl]-cyclohexanone. The preparation method comprises a following step: in the presence of a metallic reducing agent and an electrolyte, 2,2-dichloro-3-hydroxy-4,5,6-triphenyl methoxy-3-[(phenyl methoxy)methyl]-(3S,4S,5S,6R)-cyclohexanone is subjected to reductive dechlorination at 25 to 55 DEG C in a polar solvent. The preparation method is capable of reducing application of toxic and expensive reagents, increasing yield, and reducing raw material cost greatly, is friendly to the environment, and is more suitable of industrialized production.
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Paragraph 0026; 0027
(2016/11/17)
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- 1-Silyl-2,6-diketones: Versatile intermediates for the divergent synthesis of five- and six-membered carbocycles under radical and anionic conditions
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1-Silyl-2,6-diketones, readily prepared by addition of (silylmethyl)metal reagents to 1,5-lactols followed by oxidation of the resultant diols, can be efficiently transformed into 3-hydroxycyclohexanones, cyclohex-2-enones, or 1-(silylmethyl)cyclopentane-1,2-diols under nucleophilic, basic, or single electron-transfer reduction conditions, respectively. The latter cyclitols can be further transformed into 2-methylenecyclopentanols or 1-(hydroxymethyl) cyclopentane-1,2-diols by Peterson elimination or Tamao-Fleming oxidation, respectively.
- Chiara, Jose L.,Garcia, Angela,Sesmilo, Esther,Vacas, Tatiana
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p. 3935 - 3938
(2007/10/03)
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- PROCESSES FOR THE PURIFICATION OF VOGLIBOSE AND INTERMEDIATES THEREOF
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Processes for the purification of voglibose are provided. Also provided are processes for the purification of substituted or unsubstituted 5-oxo-1,2,3,4-cyclohexanetetrol and substituted 5-amino-1,2,3,4-cyclohexanetetrol, which compounds are useful intermediates in the preparation of voglibose.
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Page/Page column 9-10
(2008/06/13)
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- PROCESS FOR THE PREPARATION OF 1,2,3,4-CYCLOHEXANETETROL DERIVATIVES
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Provided herein are processes for the preparation of 1,2,3,4-cyclohexanetetrol derivatives, which are useful intermediates for the synthesis of voglibose; processes for the preparation of substituted 2,3,4,5-tetrahydroxycyclohexanone; and processes for preparing voglibose. Also provided are compounds formed by such processes.
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Page/Page column 15
(2008/06/13)
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- Synthesis of 5-epi-[6-2H2]valiolone and stereospecifically monodeuterated 5-epi-valiolones: Exploring the steric course of 5-epi-valiolone dehydratase in validamycin A biosynthesis
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In validamycin A biosynthesis, as well as that of acarbose, the valienamine and validamine moieties are ultimately derived from a C7 sugar, sedoheptulose 7-phosphate, which is cyclized to 2-epi-5-epi-valiolone by a cyclase that operates via a dehydroquinate (DHQ) synthase-like mechanism. 2-epi-5-epi-Valiolone is first epimerized at C-2 to give 5-epi-valiolone and then dehydrated between C-5 and C-6 to yield valienone. To probe the dehydration mechanism of 5-epi-valiolone to valienone, stereospecifically 6α- and 6β-monodeuterated 5-epi-valiolones were synthesized. The key step in the synthesis was desulfurization of the tetrabenzyl-6,6-bis(methylthio)-5-epi-valiolone and introduction of the deuterium utilizing Zn, NiCl2, ND4Cl/D2O, and THF. Extensive studies using various combinations of protio- and deuteroreagents and solvents probed the mechanism of the reductive desulfurization, which is crucial for the preparation of stereospecifically monodeuterated 5-epivaliolones. Incorporation experiments with the labeled precursors in the validamycin A producer strain, Streptomyces hygroscopicus var. limoneus, revealed that the dehydration of 5-epi-valiolone to valienone occurs by a syn elimination of water.
- Mahmud,Xu,Young Ung Choi
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p. 5066 - 5073
(2007/10/03)
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- A highly efficient and shortcut synthesis of cyclitol derivatives via spiro sugar ortho esters
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Preparation of cyclitol derivatives from sugar lactones via spiro sugar ortho esters is described. The key steps are the novel enol ether formation from sugar ortho esters with A1Me3 and the efficient intramolecular aldol cyclization of alkyl enol ethers with ZnCl2 in THF/H2O. Firstly, the spiro sugar ortho esters 3a-c were prepared from the benzyl protected sugar lactones 1a-c and 2,2-dimethylpropanediol (2). These ortho esters were efficiently converted into the enol ethers 5a-c by the treatment of AlMe3 in CH2Cl2. The initial step of this reaction was the pyran ring cleavage accompanied by the methyl anion insertion, and the second was the dioxane ring opening caused by the Lewis acidity of AlMe3. The resulting alkyl enol ethers were treated with DMSO/Ac2O, and the formed keto compounds were converted into the carbasugars 9a-c by the ZnCl2-catalyzed aldol cyclization in THF/H2O. The overall yields of 9a, 9b, and 9c based on the corresponding lactones 1a-c were 64, 64, and 54%, respectively. (C) 2000 Elsevier Science Ltd.
- Ohtake, Hiro,Li, Xiao-Liu,Shiro, Moto,Ikegami, Shiro
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p. 7109 - 7122
(2007/10/03)
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- Facile ring transformation from gluconolactone to cyclitol derivative via spiro sugar ortho ester
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(Formula presented) A short step preparation of cyclitol derivative 8 which is a versatile synthon for the synthesis of valiolamine and its related compounds is described. Key steps in this preparation are a novel enol ether formation from spiro sugar ortho esters with AIMe3 and an intramolecular Aldol condensation of alkyl enol ethers catalyzed by ZnCl2 in THF-H2O. With these reactions, gluconolactone derivative 1 was efficiently converted into 8 in short steps.
- Ohtake, Hiro,Ikegami, Shiro
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p. 457 - 459
(2007/10/03)
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