- Expeditious synthesis of polyacetylenic water hemlock toxins and their effects on the major GABAA receptor isoform
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Classical synthetic approaches to highly unsaturated polyene/yne natural products rely on iterative cross-coupling of linear fragments. Herein, we present an expeditious and unified approach to the unsaturated backbone of polyacetylenes via domino cuprate addition/4π-electrocyclic ring opening of a stereodefined cyclobutene intermediate. This sets the stage for a detailed biological assessment of the role of Virol A and Cicutoxin as inhibitors of GABA induced chloride currents, providing further insight into the interaction of these highly potent toxins towards the GABAA receptor, including the structure-activity relationship of the derivatives.
- Berger, Martin,Chen, Yong,Bampali, Konstantina,Ernst, Margot,Maulide, Nuno
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supporting information
p. 2008 - 2011
(2018/03/01)
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- Use of flash vacuum thermolysis in a stereocontrolled synthesis of optically active alkyl-substituted cyclopentenones with fragrant properties
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The synthesis of four pairs of enantiopure antipodal substituted cyclopentenones is described. The synthetic sequences first comprise the preparation of a tricyclo[5.2.1.02,6]deca-4,8-dienone system, a subsequent kinetic enzymatic resolution of the appropriately functionalized tricyclic system, followed by a series of chemical transformations to install the desired substituents, and finally a retro Diels-Alder reaction using flash vacuum thermolysis to give the target products in high chemical and optical yields. The strategy makes effective use of the concept of transient chirality involving complete stereochemical control over reactions with the chiral tricyclic systems before thermal removal of the cyclopentadiene.
- Zwanenburg, Binne,Volkers, Andries A.,Klunder, Antonius J. H.
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p. 1234 - 1242
(2014/10/16)
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- Facial selectivity in the addition of lithium dimethylcuprate to 6-substituted tricyclo[5.2.1.02,6]deca-4,8-dienones. Synthesis of β-substituted cyclopentenones using flash vacuum thermolysis
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The stereoselectivity of the nucleophilic addition of lithium dimethylcuprate and lithium di-n-pentylcuprate to 6-substituted tricyclo[5.2.1.02,6]deca-4,8-dienones was investigated. It was shown that substituents at the 6-position can either exert a steric effect or an electronic effect. Steric approach control predominantly giving the endo product was observed for 6-alkyl substituents. Stereoelectronic control could be adequately rationalised using the Cieplak model. Flash vacuum thermolysis was used to prepare a series of β-substituted cyclopentenoids. The sequence leading to cyclopentenoids has an attractive scope.
- Klunder, Antonius J. H.,Volkers, Andries A.,Zwanenburg, Binne
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p. 1243 - 1250
(2014/11/07)
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- Method for producing alkyl-bridged ligand systems and transition metal compounds
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The invention relates to a method for producing highly substituted alkyl-bridged ligand systems on the basis of indene derivatives and transition metal compounds. Said alkyl-bridged ligand systems can be obtained in high yields using this method.
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- Stereoselective Synthesis of 2Z,4E-Dienals by Addition of Organometallic Reagents to Pyrylium Perchlorate
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A facile and stereoselective approach to 2Z,4E-dienals and derived products is presented.The method involves addition of an organometallic reagent to a pyrylium salt, followed by electrocyclic ring-opening of the intermediate 2H-pyran, to give the desired Z,E-dienal, usually with greater than 95percent stereochemical purity.These dienals may be trapped in situ with a second organometallic reagent, or oxidised or redused, without loss of stereochemical integrity.The synthesis of (1,3Z,5E)-undeca-1,3,5-triene, a component of the essential oils of the brown Hawaiian seaweeds Dictyopteris plagiogramma and D. australis, is reported to illustrate the simplicity of the procedure.
- Furber, Mark,Herbert, John M.,Taylor, Richard J. K.
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p. 683 - 690
(2007/10/02)
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