- Synthesis of the ABCD fragment of gymnocin-B
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A convergent synthesis of the ABCD fragment of gymnocin-B was accomplished. The tetracyclic ether ring system was synthesized by the construction of the BC ring system via the oxiranyl anion alkylation and ring expansion reaction, followed by the formation of the five-membered A-ring via a stereoselective radical cyclization reaction of a neopentyl-type iodide.
- Sakai, Takeo,Hata, Kohei,Kitamura, Yuki,Ishibashi, Renji,Mori, Yuji
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supporting information
(2019/11/11)
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- Synthesis of 2-C-methylerythritols and 2-C-methylthreitols via enantiodivergent Sharpless dihydroxylation of trisubstituted olefins
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The mevalonate-independent pathway (MIP) is an interesting avenue for antimicrobial lead discovery. Here, we present a unified enantioselective synthesis of all four stereoisomers of 2-C-methyltetrol. These are useful building blocks of many bioactive natural products, including 2-C-methylerythritol phosphate (MEP) of the MIP biosynthetic pathway.
- Ghosh, Shibaji K.,Butler, Mark S.,Lear, Martin J.
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p. 2706 - 2708
(2012/07/27)
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- Development of a compound-specific carbon isotope analysis method for 2-methyltetrols, biomarkers for secondary organic aerosols from atmospheric isoprene
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The stable carbon isotope compositions of 2-methyltetrols, biomarker compounds for secondary organic aerosols formed from isoprene in the atmosphere, have been determined by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). In this work, isoprene with various δ13C values was used to produce 2-methyltetrols via an oxidation reaction with hydrogen peroxide in sulfuric acid under direct sunlight. The target compounds with different stable carbon isotope compositions were then derivatized by methylboronic acid with a known δ13C value and measured by GC/C/IRMS. With δ13C values of 2-methyltetrols and methylboronic acid predetermined, isotopic fractionation is evaluated for the derivatization process. Through reduplicate δ13C measurements, the carbon isotope analysis achieved excellent reproducibility and high accuracy with an average error of 13C values range from -0.10 to 0.29%, indicating that the derivatization process does not introduce isotopic fractionation. The δ13C values of 2-methyltetrols could be calculated on the basis of the stoichiometric mass balance equation among 2-methyltetrols, methylboronic acid, and methylboronate derivatives. Preliminary tests of 2-methyltetrols in PM2.5 aerosols at two forested sites were conducted and revealed significant differences in their isotope compositions, implying possible application of the method in helping us understand the primary emission, photochemical reaction, or removal processes of isoprene in the atmosphere.
- Li, Qiang,Wang, Wu,Zhang, Hong-Wei,Wang, Yang-Jun,Wang, Bing,Li, Li,Li, Huai-Jian,Wang, Bang-Jin,Zhan, Jie,Wu, Mei,Bi, Xin-Hui
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experimental part
p. 6764 - 6769
(2011/04/26)
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- Dihydroxylation of 4-substituted 1,2-dioxines: A concise route to branched erythro sugars
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(Chemical Equation Presented) The synthesis of 2-C-branched erythritol derivatives, including the plant sugar (±)-2-C-methylerythritol 2, was achieved through a dihydroxylation/reduction sequence on a series of 4-substituted 1,2-dioxines 3. The asymmetric dihydroxylation of 1,2-dioxines was examined, providing access to optically enriched dihydroxy 1,2-dioxanes 4. The synthesized 1,2-dioxanes were converted to other erythro sugar analogues and tetrahydrofurans through controlled cleavage of the endoperoxide linkage.
- Robinson, Tony V.,Pedersen, Daniel Sejer,Taylor, Dennis K.,Tiekink, Edward R. T.
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supporting information; experimental part
p. 5093 - 5096
(2009/10/17)
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- Concise asymmetric syntheses of the (+)-2-C-methyltetritol isomers
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Two brief and facile syntheses of the title compounds have been developed using the diastereocontrolled addition of organometallics to a (R)-cyclohexylideneglyceraldehyde-derived ketone as the key steps. The addition of vinylmagnesium bromide to the ketone gave a 1:1 diastereomeric mixture of separable tertiary alcohols, which were converted to the target erythri- and threitols. On the other hand, the reaction of a dithianyl anion with the ketone gave only the single stereoisomer of a tertiary alcohol, which was converted to erythritol.
- Sharma, Anubha,Das, Priyadip,Chattopadhyay, Subrata
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experimental part
p. 2167 - 2170
(2009/04/11)
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- Chemo-enzymatic synthesis of all isomers of 2-methylbutane-1,2,3,4-tetraol - Important contributors to atmospheric aerosols
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By a combination of stereospecific osmium catalyzed oxidation of dimethyl citraconate and lipase catalysed enantioselective resolution of the formed dimethyl (2R*,3S*)-2,3-dihydroxy-2-methylbutanedioate, followed by reduction, (2R,3S)- and (2S,3R)-2-methylbutane-1,2,3,4-tetraol were isolated. Similar reactions starting with dimethyl mesaconate gave the isomers, (2R,3R)- and (2S,3S)-2-methylbutane-1,2,3,4-tetraol. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Moen, Anders Riise,Ruud, Kjersti,Anthonsen, Thorleif
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p. 1262 - 1266
(2008/09/17)
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- Asymmetric synthesis of (S,S)- and (R,R)-2-methylthreitol
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The asymmetric synthesis of (S,S)- and (R,R)-2-methylthreitol was carried out, starting from the SAMP or RAMP hydrazone of 2,2-dimethyl-1,3-dioxan-5-one. The protocol involves an enantioselective α-alkylation as a key step. The second stereogenic center was installed by either nucleophilic 1,2-addition or diastereoselective epoxidation with bis(acetylacetonato)oxovanadium(IV) [VO(acac)2] as catalyst. The title compounds were obtained in excellent diastereo- and enantiomeric excesses (≥98% de, 98% ee) and in good overall yields (40-61%). Georg Thieme Verlag Stuttgart.
- Enders, Dieter,Peiffer, Evelyn,Raabe, Gerhard
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p. 1021 - 1026
(2008/02/02)
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- The dioxanone approach to (2S,3R)-2-C-methylerythritol 4-phosphate and 2,4-cyclodiphosphate, and various MEP analogues
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(Chemical Equation Presented) Efficient syntheses of the non-mevalonate pathway intermediates 2-C-methylerythritol 4-phosphate (MEP) and 2-C-methylerythritol 2,4-cyclodiphosphate (ME-2,4-cycloPP), as well as the parent tetrol 2-C-methylerythritol, in enantiopure form from (2S,4R)-cis-2-phenyl-4-tert-butyldimethylsilyloxy-1,3-dioxan-5-one are reported. The 2S configuration of the C-methyl group was installed by highly axial-face selective addition of CH3MgBr (20:1) to the chiral dioxanone carbonyl group. Primary selective monophosphorylation and 2,4-bis-phosphorylation, followed by desilation and hydrogenolysis to the free mono-and diphosphates, and, in the latter case, cyclization to form the eight-membered phosphoryl anhydride, afforded MEP and ME-2,4-cycloPP in good yields. The C2 epimeric analogues, 2-C-methylthreitol and its 4-phosphate, were accessed by LiAlH 4 reduction of the cis,cis epoxide of (2S,4R)-4-tert- butyldimethylsilyloxymethyl-5-methylene-2-phenyl-1,3-dioxane, primary-selective phosphorylation, and cleavage of the silyl, benzylidene, and benzyl protecting groups. Regioselective cleavage of the acetal ring of 1,3-benzylidene 2-C-methylerythritol silyl ether by ozonolysis afforded a 1,2,3-triol 3-monobenzoate intermediate that was converted to the novel amino sugar, 1-amino-1-deoxy-2-C-methylerythritol.
- Lagisetti, Chandraiah,Urbansky, Marek,Coates, Robert M.
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p. 9886 - 9895
(2008/03/28)
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- Synthesis of Enantiopure 2-C-Methyl-D-erythritol 4-Phosphate and 2,4-Cyclodiphosphate from D-Arabitol
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(Equation presented) Two key intermediates of the newly discovered mevalonate-independent pathway for isoprenoid biosynthesis were prepared. Optically pure 2-C-methyl-D-erythritol 4-phosphate and 2,4-cyclodiphosphate were chemically synthesized from D-arabitol using a convenient benzylidene and tert-butyldimethylsilyl protection of polyhydroxylated intermediates. The new scheme offers a straightforward route to analogues and labeled forms.
- Urbansky, Marek,Davis, Chad E.,Surjan, Jacob D.,Coates, Robert M.
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p. 135 - 138
(2007/10/03)
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- Nucleic acid sequences to proteins involved in isoprenoid synthesis
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Methods are provided for producing plants and seeds having altered isoprenoid content and compositions. The methods find particular use in increasing the isoprenoid levels in plants, and in providing desirable isoprenoid compositions in a host plant cell.
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- Synthesis of 2-methyl-D-erythritol via epoxy ester-orthoester rearrangement
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The biomimetic epoxy ester-orthoester rearrangement has been applied to a new synthesis of 2-methyl-D-erythritol, a branched five-carbon sugar of importance to the deoxyxylulose pathway of isoprenoid biosynthesis. The intermediate orthoacetate is one of the few [2.2.1]-orthoesters to have been reported. Labeling studies with O-18 indicated that this reaction proceeds exclusively via a 5-exo cyclization. NMR analysis of chiral esters indicated an ee of 87% for the starting epoxide and an ee of 86% for the product. This route represents a rapid and convenient method for the synthesis of 2-methyl-D-erythritol and is expected to be useful for generating isotopically labeled intermediates for biochemical studies.
- Giner, Jose-Luis,Ferris Jr., William V.,Mullins, Joseph J.
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p. 4856 - 4859
(2007/10/03)
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- Simple and versatile synthesis of branched polyols: (+)-2-C-methylerythritol and (+)-2-C-methylthreitol
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The paper reports a new approach for the enantioselective synthesis of 2-C-methyl tetrols. The procedure has been utilized for preparing methylthreitol and methylerythritol, a putative intermediate in the mevalonate-independent biosynthesis of terpenoids in bacteria, algae and higher plants. The methodology offers straightforward access to related compounds and isotopically labeled derivatives. (C) 2000 Elsevier Science Ltd.
- Fontana,Messina,Spinella,Cimino
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p. 7559 - 7562
(2007/10/03)
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- Synthesis of tritium labelled 2-C-methyl-D-erythritol, a useful substrate for the elucidation of the methylerythritol phosphate pathway for isoprenoid biosynthesis
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Free 2,C-methyl-D-erythritol is utilised for isoprenoid biosynthesis by Escherichia coli mutants lacking the two first enzymes of the methylerythritol phosphate pathway, the deoxyxylulose phosphate synthase and isomero-reductase. For feeding experiments, this tetrol was synthesised with an overall 43% yield from readily available 1,2-O-isopropylidene-α-D- xylofuranose, including the possibility of tritium labelling. (C) 2000 Elsevier Science Ltd.
- Hoeffler, Jean-Fran?ois,Grosdemange-Billiard, Catherine,Rohmer, Michel
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p. 4885 - 4889
(2007/10/03)
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- Stereochemistry of the reduction step mediated by recombinant 1-deoxy-D-xylulose 5-phosphate isomeroreductase
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(equation presented) The stereochemistry of the 1-deoxy-D-xylulose 5-phosphate (DXP) isomeroreductase reduction step has been examined using the recombinant enzyme from Synechocystis sp. PCC6803. Using [3-2H]DXP and [4S-2H]NADPH, it has been determined that the C1 pro-S hydrogen in the 2-C-methyl-D-erythritol 4-phosphate product derives from C3 of DXP, indicating that hydride attack occurs on the re face of the intermediate aldehyde. The 4S-hydride from NADPH is delivered, assigning this enzyme as a class B dehydrogenase.
- Proteau, Philip J.,Woo, Youn-Hi,Williamson, R. Thomas,Phaosiri, Chanokporn
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p. 921 - 923
(2008/02/09)
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- Biosynthesis of 2-C-methyl-D-erythritol in plants by rearrangement of the terpenoid precursor, 1-deoxy-D-xylulose 5-phosphate
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Leaves of Liriodendron tulipifera convert 1-deoxy-D-xylulose to 2-C- methyI-D-erythritol via: a skeletal-rearrangement reminiscent of the formation of terpene precursors from 1-deoxy-D-xylulose. The data suggest that 2-C-methyl-D-erythritol 4-phosphate is either an intermediate or a side product of the deoxyxylulose 4-phosphate pathway of terpenoid biosynthesis.
- Sagner, Silvia,Eisenreich, Wolfgang,Fellermeier, Monika,Latzel, Christoph,Bacher, Adelbert,Zenk, Meinhart H.
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p. 2091 - 2094
(2007/10/03)
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- Synthesis of 3-C-(hydroxymethyl)erythritol and 3-C-methylerythritol.
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3-C-(Hydroxymethyl)erythritol was prepared from 3-C-(hydroxymethyl)-2,3-O-isopropylidene-D-erythro-tetrofuranose (4) by hydrolysis followed by reduction, or by reduction followed by hydrolysis. Monotosylation of 4, followed by reduction with lithium aluminum hydride and hydrolysis, afforded 3-C-methylerythritol.
- Witczak,Whistler,Daniel
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p. 235 - 245
(2007/10/02)
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- Addition of Diazomethane and Sulfur Ylides to the Oxo-group in Derivatives of Ketoses and Aldoses. Part 2. Reactions of 1-Deoxy-3,4-O-isopropylidene-D-glycero-tetrulose and 1-Deoxy-3,4:5,6-di-O-isopropylidene-L-arabino-hexulose
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The reactions of diazomethane and dimethyloxosulfonium methylide with 1-deoxy-3,4-O-isopropylidene-D-glycero-tetrulose and 1-deoxy-3,4:5,6-di-O-isopropylidene-L-arabino-hexulose were studied.The sulfur ylide yielded two epimeric epoxides while diazomethane in addition furnished a homologous ketone.The relative yields of the three products in the reaction with diazomethane were determined with varying concentrations of methanol in the reaction medium, and the results were explained on the basis of a two-step reaction mechanism proposed earlier.Steric effects and complexation between the positive nitrogen and one of the ring oxygens were inferred to be important.Several new products were isolated and characterized.
- Anthonsen, Thorleif,Hagen, Steinar,Lwande, Wilber
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