286936-08-1Relevant academic research and scientific papers
Stereocontrolled Synthesis of (-)-Bactobolin A
Vojá?ková, Petra,Michalska, Lucyna,Ne?as, Marek,Shcherbakov, Dimitri,B?ttger, Erik C.,?poner, Ji?í,?poner, Judit E.,?venda, Jakub
, p. 7306 - 7311 (2020/05/25)
A stereoselective synthesis of the ribosome-binding antitumor antibiotic (-)-bactobolin A is reported. The presented approach makes effective use of (-)-quinic acid as a chiral pool starting material and substrate stereocontrol to establish the five contiguous stereocenters of (-)-bactobolin A. The key steps of the synthesis include a stereoselective vinylogous aldol reaction to introduce the unusual dichloromethyl substituent, a completely diastereoselective rhodium(II)-catalyzed C-H amination reaction to set the configuration of the axial amine, and an intramolecular alkoxycarbonylation to build the bicyclic lactone framework. The developed synthetic route was used to prepare 90 mg of (-)-bactobolin A trifluoroacetate in 10% overall yield.
Synthesis of the B-seco limonoid scaffold
Schuster, Hannah,Martinez, Remi,Bruss, Hanna,Antonchick, Andrey P.,Kaiser, Markus,Schuermann, Markus,Waldmann, Herbert
supporting information; experimental part, p. 6545 - 6547 (2011/07/09)
The underlying stereochemically complex and densely functionalized scaffold of the B-seco limonoids was synthesized employing an Ireland-Claisen rearrangement as key transformation.
The synthesis of 2-oxyalkyl-cyclohex-2-enones, related to the bioactive natural products COTC and antheminone A, which possess anti-tumour properties
Arthurs, Claire L.,Morris, Gareth A.,Piacenti, Michela,Pritchard, Robin G.,Stratford, Ian J.,Tatic, Tanja,Whitehead, Roger C.,Williams, Katharine F.,Wind, Natasha S.
experimental part, p. 9049 - 9060 (2011/01/04)
The syntheses of five novel 2-oxyalkyl-cyclohex-2-enones, structurally related to the natural products COTC and antheminone A, are described. The target structures were selected in order to probe the influence of several key structural parameters on in vi
(-)-Quinic acid: a versatile precursor for the synthesis of analogues of 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC) which possess anti-tumour properties
Arthurs, Claire L.,Lingley, Katharine F.,Piacenti, Michela,Stratford, Ian J.,Tatic, Tanja,Whitehead, Roger C.,Wind, Natasha S.
, p. 2410 - 2413 (2008/09/18)
Syntheses of three novel analogues of the Streptomyces metabolite COTC are described, using the versatile chiral pool starting material, (-)-quinic acid. The results of bioassays of the target compounds against two lung cancer cell lines, A549 and H460, a
Analogues of 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC) with anti-tumor properties
Arthurs, Claire L.,Wind, Natasha S.,Whitehead, Roger C.,Stratford, Ian J.
, p. 553 - 557 (2007/10/03)
The syntheses of three novel analogues of the naturally occurring cytotoxic agent COTC are described and the results of bioassays of the target compounds against two lung cancer cell lines are presented.
Lithium enolates from a (-)-quinic acid-derived cyclohexanone with a β-alkoxy leaving group: Regioselective preparation and evaluation of enolate stability towards β-elimination
Murray, Lynne M.,O'Brien, Peter,Taylor, Richard J. K.,Wünnemann, Stefan
, p. 2597 - 2601 (2007/10/03)
Deprotonation of a (-)-quinic acid-derived ketone {(2S,3S,4aR,8R,8aS)-8- [(tert-butyl(dimethyl)silyl)oxy]-2,3-dimethoxy-2,3-dimethylhexahydro-1, 4-benzodioxin-6(5H)-one} using lithium hexamethyldisilazide (LHMDS) at -78°C gave one regioisomeric enolate. The regiocontrol is governed by the axial β-silyloxy substituent and the resulting lithium enolate is stable towards β-elimination at temperatures up to -40°C. It was found that the axial β-silyloxy group could be conveniently eliminated using 2.1equiv of LHMDS at 0°C for 1h and that an equatorial β-alkoxy group was much more resistant to β-elimination. A chiral lithium amide base was used to overturn the inherent regioselectivity of ketone deprotonation with LHMDS.
Stereoselective reactions of a (-)-quinic acid-derived enone: Application to the synthesis of the core of scyphostatin
Murray, Lynne M.,O'Brien, Peter,Taylor, Richard J. K.
, p. 1943 - 1946 (2007/10/03)
(Matrix presented) A (-)-quinic acid-derived enone, with the trans-1, 2-diol protected as a 2,3-dimethoxybutanediyldioxy ketal, provides an excellent template for further highly stereoselective elaboration as exemplified by its conversion into the core of
Benzene-free synthesis of hydroquinone
Ran,Knop,Draths,Frost
, p. 10927 - 10934 (2007/10/03)
All current routes for the synthesis of hydroquinone utilize benzene as the starting material. An alternate route to hydroquinone has now been elaborated from glucose. While benzene is a volatile carcinogen derived from nonrenewable fossil fuel feedstocks, glucose is nonvolatile, nontoxic, and derived from renewable plant polysacharrides. Glucose is first converted into quinic acid using microbial catalysis. Quinic acid is then chemically converted into hydroquinone. Under fermentor-controlled conditions, Escherichia coli QP1.1/pKD12.138 synthesizes 49 g/L of quinic acid from glucose in 20% (mol/mol) yield. Oxidative decarboxylation of quinic acid in clarified, decolorized, ammonium ion-free fermentation broth with NaOCl and subsequent dehydration of the intermediate 3(R),5(R)-trihydroxycyclohexanone afforded purified hydroquinone in 87% yield. Halide-free, oxidative decarboxylation of quinic acid in fermentation broth with stoichiometric quantities of (NH4)2Ce(SO4)3 and V2O5 afforded hydroquinone in 91% and 85% yield, respectively. Conditions suitable for oxidative decarboxylation of quinic acid with catalytic amounts of metal oxidant were also identified. Ag3PO4 at 2 mol % relative to quinic acid in fermentation broth catalyzed the formation of hydroquinone in 74% yield with K2S2O8 serving as the cooxidant. Beyond establishing a fundamentally new route to an important chemical building block, oxidation of microbe-synthesized quinic acid provides an example of how the toxicity of aromatics toward microbes can be circumvented by interfacing chemical catalysis with biocatalysis.
Approaches to the synthesis of (+)- and (-)-epibatidine
Barros, M. Teresa,Maycock, Christopher D.,Ventura, M. Rita
, p. 166 - 173 (2007/10/03)
Synthetic approaches to the powerful analgesic alkaloids (+)- and (-)-epibatidine are described. The starting material employed was natural (-)-quinic acid from which chiral enones and α-iodoenones were prepared. Stille coupling afforded suitable substrat
