- Synthesis and anticancer profile of novel sphingoid base-like compounds with a quaternary stereocentre
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The synthesis of novel sphingoid base-like compounds with a quaternary stereocentre was achieved in a sequence featuring [3,3]-sigmatropic rearrangements and olefin cross-metathesis transformation as the key reaction steps, which were accompanied by the rational selection of suitable functional group transformations. The stereochemistry of the desired tetra-substituted carbon bearing nitrogen functionality was determined via NOESY experiments of the advanced oxazolidine-2-thiones. Cell viability experiments revealed significant antiproliferative/cytotoxic activity of the target compounds 7, ent-7 and 29 against the Jurkat cell line, with the IC50 values of 6.6 μM, 5.6 μM and 6.1 μM, respectively.
- Jacková, Dominika,Brunderová, Mária,Fábian, Martin,Martinková, Miroslava,Gonda, Jozef,Pilátová, Martina Bago
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- Production of optically active 2 - vinylcyclopropane - 1, 1 - dicarboxylic acid ester
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Provided is a method for producing an optically active 1-amino-2-vinylcyclopropane-1-carboxylic acid ester and 2-vinylcyclopropane-1,1-dicarboxylic acid ester, which do not isomerize during a reaction, with an inexpensive and easily obtainable optically a
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Paragraph 0058
(2018/03/31)
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- Total synthesis of pachastrissamine together with its 4-epi-congener via [3,3]-sigmatropic rearrangements and antiproliferative/cytotoxic evaluation Dedicated to Associated Professor Ladislav Knie?o on the occasion of his 70th birthday
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Synthesis of the HCl salts of two anhydrophytosphingosines, jaspine B (1) and its 4-epi-congener 5 from easily available dimethyl l-tartrate and/or l-arabinose, is described. The key transformations are the efficient incorporation of a chiral amino group
- Martinková, Miroslava,Mezeiová, Eva,Fabi?íková, Milica,Gonda, Jozef,Pilátová, Martina,Moj?i?, Ján
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- Total synthesis of pachastrissamine together with its 4-epi-congener via [3,3]-sigmatropic rearrangements and antiproliferative/cytotoxic evaluation Dedicated to Associated Professor Ladislav Knieo on the occasion of his 70th birthday
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Synthesis of the HCl salts of two anhydrophytosphingosines, jaspine B (1) and its 4-epi-congener 5 from easily available dimethyl l-tartrate and/or l-arabinose, is described. The key transformations are the efficient incorporation of a chiral amino group
- Martinkov, Miroslava,Mezeiov, Eva,Fabikov, Milica,Gonda, Jozef,Piltov, Martina,Moji, Jn
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- Reaction of (2S,3S)-2-benzyloxybutane-1,2,4-triol with N,N′-carbonyldiimidazole
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(2S,3S)-2-Benzyloxybutane-1,2,4-triol reacted with N,N′-carbonyldiimidazole to give a mixture of the expected 1,2-carbonate and the corresponding bis-carbonate.
- Selezneva,Khasanova,Egorov,Gimalova,Ovchinnikov, M. Yu.,Miftakhov
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p. 910 - 914
(2015/08/25)
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- Total Synthesis of Gelsemoxonine through a Spirocyclopropane Isoxazolidine Ring Contraction
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Plants of the species Gelsemium have found application in traditional Asian medicine for over a thousand years. Gelsemoxonine represents a novel constituent of this plant incorporating a highly functionalized azetidine at its core. We herein report a full
- Diethelm, Stefan,Carreira, Erick M.
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p. 6084 - 6096
(2015/05/27)
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- Facile synthesis of (2R,3S)-2-benzyloxy-3-hydroxybutyrolactone
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The heterocyclic diols derived from L-dimethyl tartrate are important chiral synthons in organic synthesis. In particular, L-threosolactone and L-threosolactam structures are versatile precursors for the synthesis of biologically active molecules. Structu
- El-Batta, Amer
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p. 2457 - 2463
(2013/07/25)
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- Preparation of enantioenriched tetraols and triolamines from a common epoxide
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We identify a silylcyclopentene oxide that is amenable to several distinct asymmetric catalytic transformations providing access to enantio-enriched tetraol and triol-amines. The sequence employed allows for selective protection of one amine or alcohol from the four heteroatoms that are introduced into the carbon scaffold.
- Kaviani-Joupari, Makan,Schramm, Michael P.
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supporting information
p. 5014 - 5017
(2013/09/02)
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- Development of diacyltetrol lipids as activators for the C1 domain of protein kinase C
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The protein kinase C (PKC) family of serine/threonine kinases is an attractive drug target for the treatment of cancer and other diseases. Diacylglycerol (DAG), phorbol esters and others act as ligands for the C1 domain of PKC isoforms. Inspection of the crystal structure of the PKCδ C1b subdomain in complex with phorbol-13-O-acetate shows that one carbonyl group and two hydroxyl groups play pivotal roles in recognition of the C1 domain. To understand the importance of two hydroxyl groups of phorbol esters in PKC binding and to develop effective PKC activators, we synthesized DAG like diacyltetrols (DATs) and studied binding affinities with C1b subdomains of PKCδ and PKC. DATs, with the stereochemistry of natural DAGs at the sn-2 position, were synthesized from (+)-diethyl l-tartrate in four to seven steps as single isomers. The calculated EC50 values for the short and long chain DATs varied in the range of 3-6 μM. Furthermore, the fluorescence anisotropy values of the proteins were increased in the presence of DATs in a similar manner to that of DAGs. Molecular docking of DATs (1b-4b) with PKCδ C1b showed that the DATs form hydrogen bonds with the polar residues and backbone of the protein, at the same binding site, as that of DAG and phorbol esters. Our findings reveal that DATs represent an attractive group of C1 domain ligands that can be used as research tools or further structurally modified for potential drug development.
- Mamidi, Narsimha,Gorai, Sukhamoy,Mukherjee, Rakesh,Manna, Debasis
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experimental part
p. 1275 - 1285
(2012/06/04)
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- Studies of intramolecular alkylidene carbene reactions; an approach to heterocyclic nucleoside bases
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A series of investigations into the applications of intramolecular cyclisations of alkylidene carbenes are described. The insertion reaction of the carbene generated from 1,4-di(tert-butyldimethylsilyloxy)-3-benzyloxy-butane-2-one to the benzylic position
- Hobley, Gerard,Stuttle, Keith,Wills, Martin
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p. 4739 - 4748
(2007/10/03)
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- Visible Light Initiated Photosensitized Electron Transfer Cyclizations of Aldehydes and Ketones to Tethered αβ-Unsaturated Esters: Stereoselective Synthesis of Optically Pure C-Furanosides
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Photosensitized one-electron reductive activation of aldehydes/ketones tethered with activated olefins leads to efficient cyclization to give diastereoselective cycloalkanols in high yield. The activation is promoted by secondary and dark electron transfer from visible light (405 nm) initiated photosensitized electron transfer generated 9,10-dicyanoanthracene radical anion (DCA.-). The DCA.- is produced by electron transfer using either triphenylphosphine (Ph3P) as sacrificial electron donor (PS-A) or 1,5-dimethoxynaphthalene (DMN) as primary electron donor and ascorbic acid as sacrificial electron donor (PS-B), to light-absorbing DCA. The cyclization is suggested to involve ketyl radical intermediate. High trans diastereoselectivity is observed during the formation of cycloalkanols. This cyclization strategy is further extended for the stereoselective synthesis of optically pure C-furanoside (41), starting from naturally occuring L-tartaric acid. The stereochemistry of 41 is suggested based on the single-crystal X-ray diffraction data.
- Pandey, Ganesh,Hajra, Saumen,Ghorai, Manas K.,Ravi Kumar
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p. 5966 - 5973
(2007/10/03)
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- Stereoselective syntheses and reactions of chiral oxygenated α,β-unsaturated-γ- and δ-lactones
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The syntheses of the chiral α,β-unsaturated lactones (+)-5, (-)-6, (+)-8, (+)-9, and (+)-10 have been efficiently achieved from readily available starting materials. The lactone (+)-5 has been synthesized in 7 steps from (R,R)-dimethyl tartrate (38-43% overall yield). The use of (+)-5 in formal syntheses of natural (+)-asperlin 4 and advanced intermediates for (+)-olguine 2 are also reported. The lactone (-)-6 has been prepared in 5 steps from (R)-malic and (44-50% overall yield). It can be a useful precursor for the syntheses of branched chain and deoxy nucleoside analogues. The preparation of (-)-6 constitutes formal syntheses of natural (+)-eldanolide 53 and the (+)-Geissman-Waiss lactone 54 (an intermediate for the syntheses of a variety of pyrrolizidine alkaloids). The lactones (+)-8, (+)-9 and (+)-10 have been synthesized from 3,4-di-O-acetyl-L-rhamnal 58. The highly diastereoselective transformations of (+)-9 and (+)-10, through sequential conjugate nucleophilic addition and enolate reaction, into densely functionalized chiral γ-lactones 12 are also reported. Copyright (C) Elsevier Science Ltd.
- Sanchez-Sancho, Francisco,Valverde, Serafin,Herradon, Bernardo
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p. 3209 - 3246
(2007/10/03)
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- C-Furanoside Synthesis via Radical Cyclisation of β-Alkoxyacrylates
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Stereoselective synthesis of C-furanosides is accomplished via tributylstannane-mediated radical cyclisation of β-alkoxyacrylates.
- Lee, Eun,Park, Cheol Min
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p. 293 - 294
(2007/10/02)
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- Selective Manipulation of Hydroxy Groups in (2S,3S)-Threitol
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Systematic transformation of diethyl (2R,3R)-tartrate into a number of protected or functionalized derivatives of threitol, which are important precursors for many natural products, is carried out employing reductive and oxidative cleavage reactions of be
- Takano, Seiichi,Kurotaki, Ayako,Sekiguchi, Yoshinori,Satoh, Shigeki,Hirama, Michiyasu,Ogasawara, Kunio
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p. 811 - 817
(2007/10/02)
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- THE USE OF L-TARTARIC ACID IN THE SYNTHESIS OF ENANTIOMERICALLY PURE COMPOUNDS: SYNTHESIS OF 4-O-BENZYL-2,3-DIDEOXI-L-THREO-HEX-2-ENONO-1,5-LACTONE
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The title compound was obtained through a seven steps sequence and using -dimethyl L-tartrate as the starting material (30percent overall yield).The system 2,3-dideoxy-L-threo-hex-2-enono-1,5-lactone is present in several natural compounds.
- Valverde, Serafin,Herradon, Bernardo,Martin-Lomas, M.
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p. 3731 - 3734
(2007/10/02)
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- A FACILE CLEAVAGE OF BENZYLIDENE ACETALS WITH DIISOBUTYLALUMINUM HYDRIDE
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Benzylidene acetals of 1,2- and 1,3-glycols are easily cleft by diisobutylaluminum hydride in a toluene solution at 0 deg C - room temperature to give the corresponding monobenzyl ethers of the glycols.In general the reaction proceeds excellently in regioselective manner depending on the stereochemical environment.
- Takano, Seiichi,Akiyama, Masashi,Sato, Seiji,Ogasawara, Kunio
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p. 1593 - 1596
(2007/10/02)
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- AN EFFICIENT AND STEREOSELECTIVE SYNTHESIS OF PLATELET-ACTIVATING FACTORS AND THE ENANTIOMERS FROM D- AND L-TARTARIC ACIDS
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Acetyl glyceryl ether phosphorylcholines, platelet-activating factors (1 and 2), were efficiently synthesized in a stereochemically unambiguous manner starting from D- and L- tartaric acids as the chiral synthons.
- Fujita, Kagari,Nakai, Hisao,Kobayashi, Susumu,Inoue, Keizo,Nojima, Shoshichi,Ohno, Masaji
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p. 3507 - 3510
(2007/10/02)
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