- Arene cis-dihydrodiols: Useful precursors for the preparation of analogues of the anti-tumour agent, 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC)
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The synthesis of 6-epi-COTC, a diastereoisomer of Streptomyces metabolite 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC), is described. The anti-cancer activities of the novel analogue, in racemic and enantiomerically pure forms, a
- Arthurs, Claire L.,Raftery, James,Whitby, Helen L.,Whitehead, Roger C.,Wind, Natasha S.,Stratford, Ian J.
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- Use of Electrochemical Methods as an Alternative to Tin Reagents for the Reduction of Vinyl Halides in Inositol Synthons
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Several vinyl halides previously used in inositol syntheses were subjected to electrochemical reduction. The unreactivity of allylic alcohols or allylic ethers at the applied potentials allowed the selective reduction of vinyl halides to olefins. Electrochemical methods provide for selective reduction of vinyl iodides over vinyl bromides, with better yields than analogous tin methodology. Cinnamyl ethers were reductively cleaved at -3.2 V (vs Ag/AgNO3) in the presence of alkyl allyl ethers to provide selective deprotection. The electrochemical reduction of vinyl halides in the presence of a vinyloxirane or vinylaziridine is accompanied by the solvolysis of the strained rings. Yields and conditions are reported and compared to those from standard tin-induced dehalogenation.
- Hudlicky, Tomas,Claeboe, Christopher D.,Brammer Jr., Larry E.,Koroniak, Lukasz,Butora, Gabor,Ghiviriga, Ion
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- A chemoenzymatic route to chiral siloxanes
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An approach employing two enzymes—toluene dioxygenase and immobilized lipase B from Candida antarctica (N435)—was explored as a potential biocatalytic method for the coupling of chiral diols with siloxane species. Analysis of reaction mixtures using1H NMR spectroscopy suggested that up to 66% consumption of the siloxane starting materials had occurred. Oligomeric species were observed and chiral products from the coupling of a cyclic diol with a siloxane molecule were isolated and characterized by MALDI-ToF MS and GPC. Immobilized lipases from Rhizomucor miehei and Thermomyces lanuginosus were also explored as potential catalysts for the coupling reactions, however, their use only returned starting material.
- Naoum, Ravi,Séguin, Jacqueline P.,Trant, John F.,Frampton, Mark B.,Hudlicky, Tomá?,Zelisko, Paul M.
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p. 4027 - 4031
(2016/07/06)
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- Toluene dioxygenase-mediated oxidation of dibromobenzenes. Absolute stereochemistry of new metabolites and synthesis of (-)-conduritol E
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Dibromobenzenes (o-, m-, and p-isomers) were converted to the corresponding cis-cyclohexadiene diols by whole-cell fermentation with Escherichia coli JM 109 (pDTG601A), an organism over-expressing the enzyme toluene dioxygenase (TDO). Absolute stereochemi
- Finn, Kevin J.,Collins, Jonathan,Hudlicky, Tomas
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p. 7471 - 7476
(2007/10/03)
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- Synthesis of chiral ADMET polymers containing repeating D-chiro-inositol units derived from a biocatalytically prepared diene diol
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Several chiral hydroxylated polymers have been prepared, via ADMET techniques, from the diene diol derived from bromobenzene, obtained by means of whole-cell fermentation with Escherichia coli (JM109 pDTG601).
- Bui, Vu P.,Hudlicky, Tomas
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p. 641 - 646
(2007/10/03)
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- Selective electrochemical reduction of cinnamyl ethers in the presence of other allylic C-O bonds
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Several conduritol derivatives protected as allyl and cinnamyl ethers were subjected to electrochemical reduction at a mercury cathode, resulting in selective removal of the cinnamyl group.
- Solis-Oba, Aida,Hudlicky, Tomas,Koroniak, Lukasz,Frey, Dean
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p. 1241 - 1243
(2007/10/03)
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- Enantiopure arene dioxides: Chemoenzymatic synthesis and application in the production of trans-3,4-dihydrodiols
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Enantiopure syn- and anti-arene dioxides are synthesised from cis-dihydrodiol metabolites; anti-benzene dioxides are reduced to enantiopure trans-3,4-dihydrodiols while synbenzene dioxides racemise thermally via 1,4-dioxocins.
- Boyd,Sharma,O'Dowd,Hempenstall
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p. 2151 - 2152
(2007/10/03)
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- Chemoenzymatic enantiodivergent synthesis of 1,2-dideoxy-2-amino-1- fluoro-allo-inositol
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Both enantiomers of dideoxyfluoroamino inositols (+)-9 and (-)-9 were synthesized from bromocyclohexadiene cis-diol 1 obtained by microbial oxidation of bromobenzene with toluene dioxygenase. Selective introduction of the amino group was achieved through S(N)2 displacement of triflates 7, 11. Fluorine was selectively introduced via trans-diaxial epoxide opening with tetrabutylphosphonium fluoride dihydrofluoride (TBPF-DF).
- Oppong, Kofi A.,Hudlicky, Tomas,Yan, Fengyang,York, Chentao,Nguyen, Ba V.
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p. 2875 - 2880
(2007/10/03)
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- A practical multigram-scale synthesis of allo-inositol
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Allo-Inositol was prepared on a multigram scale starting with bromobenzene in seven steps by three different cis-dihydroxylations (enzymatic, OsO4 and RuO4 catalyzed) employed in tandem.
- Desjardins, Michel,Brammer Jr., Larry E.,Hudlicky, Tomas
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- Biocatalysis as a Rational Approach to Enantiodivergent Synthesis of Highly Oxygenated Compounds: (+)- and (-)-Pinitol and Other Cyclitols
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Bacterial oxygenation of halogenated aromatic compounds yields arene cis-diols of type 2 of high enantiomeric purity.Further oxygenation of these extremely versatile synthetic intermediates provides for stereo- and regioselective introduction of additional functionalities such as hydroxyl groups.Several rational methods of oxygenation (epoxidation, osmylation, singlet oxygen addition, and ozonolysis) are used to produce, in short synthetic routes, cyclitol derivatives of medicinal importance.Proper symmetry considerations lead to the development of enantiodivergent synthetic design of target compounds from a single enantiomer of a starting diol.These principles are ilustrated on the short syntheses of (+)- and (-)-pinitol.Stereocontrolled oxidative transformation of diols of type 2 are exemplified in the synthesis of conduritol C and dihydroconduritol C.Full experimental details are provided for all compounds.A guide to the stereorational design of any stereoisomer of cyclohexane (poly)ols or carbohydrates is provided at the end of the paper.
- Hudlicky, Tomas,Rulin, Fan,Tsunoda, Toshiya,Luna, Hector,Andersen, Catherine,Price, John D.
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p. 229 - 238
(2007/10/02)
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