- General Strategy for the Synthesis of Rare Sugars via Ru(II)-Catalyzed and Boron-Mediated Selective Epimerization of 1,2- trans-Diols to 1,2- cis-Diols
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Human glycans are primarily composed of nine common sugar building blocks. On the other hand, several hundred monosaccharides have been discovered in bacteria and most of them are not readily available. The ability to access these rare sugars and the corresponding glycoconjugates can facilitate the studies of various fundamentally important biological processes in bacteria, including interactions between microbiota and the human host. Many rare sugars also exist in a variety of natural products and pharmaceutical reagents with significant biological activities. Although several methods have been developed for the synthesis of rare monosaccharides, most of them involve lengthy steps. Herein, we report an efficient and general strategy that can provide access to rare sugars from commercially available common monosaccharides via a one-step Ru(II)-catalyzed and boron-mediated selective epimerization of 1,2-trans-diols to 1,2-cis-diols. The formation of boronate esters drives the equilibrium toward 1,2-cis-diol products, which can be immediately used for further selective functionalization and glycosylation. The utility of this strategy was demonstrated by the efficient construction of glycoside skeletons in natural products or bioactive compounds.
- Li, Xiaolei,Tang, Weiping,Wu, Jicheng
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p. 3727 - 3736
(2022/03/02)
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- Practical synthesis of 2-deoxy sugars via metal free deiodination reactions
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2-Deoxy-glycosides, in which the C-2 hydroxyl group is replaced with a hydrogen atom, are important motifs in numerous bioactive natural products and pharmaceutical molecules. Herein, an improved dilauroyl peroxide-mediated radical deiodination reaction b
- Yao, Wang,Wang, Hao,Zeng, Jing,Wan, Qian
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p. 454 - 478
(2022/01/20)
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- A One-Pot Method for Removal of Thioacetyl Group via Desulfurization under Ultraviolet Light to Synthesize Deoxyglycosides
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We herein developed an efficient method for removing thioacetyl to synthesize acylated deoxy glycosides in a one-pot reaction, where the thioacetyl was selectively deacetylated by hydrazine hydrate in DMF within 2-5 min at room temperature, followed by de
- Ge, Jian-Tao,Zhou, Lang,Luo, Tao,Lv, Jian,Dong, Hai
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supporting information
p. 5903 - 5906
(2019/08/26)
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- TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals
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The thio-additions of glycals were efficiently promoted by a stoichiometric amount of trimethylsilyl bromide (TMSBr) to produce S-2-deoxyglycosides under solvent-free conditions in good to excellent yields. In addition, with triphenylphosphine oxide as an additive, the TMSBr-mediated direct glycosylations of glycals with a large range of alcohols were highly α-selective.
- Hsu, Mei-Yuan,Liu, Yi-Pei,Lam, Sarah,Lin, Su-Ching,Wang, Cheng-Chung
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supporting information
p. 1758 - 1764
(2016/10/05)
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- Ferrier rearrangement and 2-deoxy sugar synthesis from d-glycals mediated by layered α-zirconium sulfophenylphosphonate-methanphosphonate as heterogeneous catalyst
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Layered α-zirconium sulfophenylphosphonate-methanphosphonate is a solid acid catalyst that catalyzes Ferrier rearrangement from d-glycals and alcoholic nucleophiles under mild reaction conditions in short time and good yields. Notably, the combination of α-zirconium sulfophenylphosphonate- methanphosphonate and lithium bromide change the regioselectivity of this process affording 2-deoxy sugars in good yields. Graphical Abstract: [Figure not available: see fulltext.]
- Rosati, Ornelio,Curini, Massimo,Messina, Federica,Marcotullio, Maria Carla,Cravotto, Giancarlo
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p. 169 - 175
(2013/03/13)
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- A chiron approach to (-)-tetrahydrolipstatin
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An efficient chiron approach to the total synthesis of (-)- tetrahydrolipstatin is described. The main features of the synthetic strategy, which starts from tri-O-acetyl-D-glucal, are copper-mediated C-C bond formation, Frater alkylation, and Barton-McCombie deoxygenation. Georg Thieme Verlag Stuttgart.
- Yadav,Vishweshwar Rao,Prasad
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p. 3888 - 3894
(2008/02/09)
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- Synthetic studies on antascomicin A: Construction of the C18-C34 fragment
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Stereoselective synthesis of the C18-C34 fragment of antascomicin A is described. Construction of the C27-C34 carbocycle moiety was achieved via catalytic Ferrier carbocylization and Johnson-Claisen rearrangement, which was converted to iodide 2 by use of
- Fuwa, Haruhiko,Okamura, Yumiko,Natsugari, Hideaki
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p. 5341 - 5352
(2007/10/03)
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- Synthesis of a-ring synthon of 19-nor-1alpha,25-dihydroxyvitamin D3 from (D)-glucose
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The present invention provides a method for the synthesis of an A-ring synthon phosphine oxide used in the preparation of 19-nor vitamin D compounds, and to novel synthetic intermediates formed during the synthesis. The new method prepares the phosphine oxide from (D)-glucose.
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- Novel synthesis of 2-substituted 19-norvitamin D A-ring phosphine oxide from D-glucose as a building block
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19-Norvitamin D A-ring phosphine oxide 5 was synthesized by a new sequence mode starting from D-glucose as a chiral template. Transformation of the pyranoside ring into the A-ring carbocycle was achieved by the Pd-catalyzed Ferrier rearrangement. The phosphine oxide 5 was obtained in an 18% overall yield by this novel cost-effective method.
- Shimizu, Masato,Iwasaki, Yukiko,Shibamoto, Yoshinori,Sato, Miki,DeLuca,Yamada, Sachiko
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p. 809 - 812
(2007/10/03)
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- Indium-mediated stereospecific glycosylation of alcohols
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Indium has been shown to be effective in the stereospecific glycosylation of various alcohols with bromosugars.
- Banik, Bimal K.,Samajdar, Susanta,Indrani, Banik,Zegrocka, Oliwia,Becker, Frederick F.
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p. 227 - 230
(2007/10/03)
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- Synthesis and structural studies of branched 2-linked trisaccharides related to blood group determinants
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A series of trisaccharide glycosides, Fuc-(1 → 2)-β-Gal-(1 → 3)-β-X-OMe (X = GlcNAc, Glc, 2-deoxy-Glc) related to the blood group determinant Le(d) have been synthesised both as their α and β-Fuc anomers together with the component disaccharide starting compounds. The conformational properties of the six trisaccharides together with their parent disaccharides have been investigated by NMR spectroscopy (proton and carbon chemical shifts and proton NOEs) in combination with computer modeling using the Monte Carlo approach and the HSEA force field using the GEGOP programme. The interaction between the terminal fucose unit and the reducing unit was probed by substitution of the bulky NAc group with hydroxyl and deoxy substituents, respectively. Compounds with severe steric interactions were identified by the non-additivity of their carbon chemical shifts. This was subsequently confirmed by the detailed conformational assessment by NOE spectroscopy and computer modeling. The most severe contacts arose in the α-L-Fuc derivatives, whereas the β-linked L-Fuc derivatives only in one case exhibit severe steric interaction as probed by the NMR parameters.
- Duus, Jens .,Nifant'ev, Nikolay,Shashkov, Alexander S.,Khatuntseva, Elena A.,Bock, Klaus
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- STRAIGHTFORWARD HOMOCHIRAL SYNTHESIS OF THE LACTONE MOIETY OF MEVINIC ACIDS
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A new straightforward synthesis of the common lactone moiety of mevinic acids is described starting form tri-O-acetyl-D-glucal 2.The key diastereoselective O-glycosidation of 2 with methanol and subsequent methanolysis and tritylation are incorporated in
- France, Christopher J.,McFarlane, Ian M.,Newton, Christopher G.,Pitchen, Philippe,Webster, Michael
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p. 1635 - 1638
(2007/10/02)
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- Ferric chloride, an anomerization catalyst for the preparation of alkyl α-glycopyranosides
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Anhydrous FeCl3 in CH2Cl2 has been found to readily anomerize β-glycopyranosides to their corresponding α-anomers in good yields and selectivities at room temperatures. Acetyl- and benzoyl-protected oxygen sugars yielded the best results.
- Ikemoto, Norihiro,Kim, Oak Kyung,Lo, Lee-Chiang,Satyanarayana, Vunnam,Chang, Mayland,Nakanishi, Koji
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p. 4295 - 4298
(2007/10/02)
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