- Efficient Synthesis of (+/-)-Solavetivone and (+/-)-2H2>Solavetivone
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An alternative and efficient synthesis of the title compounds is described.The synthesis involves cycloaddition of 2-methylene-4-methoxy-6-methyl-4-cyclohexenylacetonitrile with methyl vinyl ketone as a key step.
- Murai, Akio,Sato, Shingo,Masamune, Tadashi
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Read Online
- Synthesis based on cyclohexadienes. Part 34. A tandem cationic rearrangement-ene cyclisation route to 2-pupukeanone
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A tandom cationic rearrangement-ene cyclisation route to 2-pupukeanone was discussed. The synthesis of 2-pupukeanone was done using a one-pot tandom acid-catalysed rearrangement. Results showed that 2-pupukeanone could be obtained from the tricyclic keton
- Biju, P. John,Kaliappan, Krishna,Laxmisha,Subba Rao
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- Ring-closing metathesis as a key step to construct the 2, 6-dihydropyrano[2, 3-c]pyrazole ring system
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A simple and efficient synthetic route to the 2, 6-dihydropyrano[2, 3-c]pyrazole ring system was developed by employing ring-closing metathesis (RCM) as a key step. The required diene substrate for the RCM reaction was prepared by a three-step procedure s
- Bieliauskas, Aurimas,Krik?tolaityte, Sonata,Holzer, Wolfgang,?ackus, Algirdas
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- Synthesis of A-Ring Precursors of 1α,25-Dihydroxyvitamin D3 Analogues Functionalized at C-2
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A flexible approach to an A-ring building block for new 1α,25-dihydroxyvitamin D analogues functionalized at C-2 as potential clinical candidates is described. The synthesis of alcohol 5 starts from (R)-carvone, and uses a Criegee rearrangement to selecti
- Sigüeiro, Rita
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Read Online
- "Umgepolte" 1.3-diaza-fulvene
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6-Subtituted 2.4-diamino-1.3-diazafulvenes with inverse fulvene polarity are readily available from 2.4.5.-tris-(diethylamino)-4-ethoxy-4H-imidazole and active methylene compounds.
- Gompper, Rudolf,Bichlmayer, Klaus Peter
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- Synthesis and photodynamic properties of pyrazole-indole hybrids in the human skin melanoma cell line G361
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Three conjugated pyrazole-indole hybrids, 5, 7 and 10, were synthesized from easily accessible 3-(hexyloxy)-1-phenyl-1H-pyrazole-4-carbaldehyde 1 and 5-iodo-3,3-dimethyl-2-phenyl-3H-indole 4 employing olefination reactions (Wittig, Ramirez), Vilsmeier-Haa
- ?a?kus, Algirdas,?ukauskait?, Asta,Bieliauskas, Aurimas,Ho?íková, Barbora,Kleizien?, Neringa,Kolá?ová, Hana,Kry?tof, Vladimír,Malina, Luká?,Simerská, Helena,Varvuolyt?, Gabriel?
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- Synthesis of 4-(1,5,9-Trimethyl-1-vinyl-4,8-decadienyl)catechol Dimethyl Ether
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Synthesis of 4-(1,5,9-trimethyl-1-vinyl-4,8-decadienyl)catechol dimethyl ether has been described utilizing Wittig reaction for the introduction of vinylic substituent at the quaternary carbon.
- Anand, Ramesh Chander,Ranjan, Harish
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- Total synthesis of amphilectane-type diterpenoid (±)-7- isocyanoamphilecta-11(20),15-diene
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The total synthesis of amphilectane-type diterpenoid (±)-7- isocyanoamphilecta-11(20),15-diene, isolated from the tropical marine sponge Cymbastela hooperi, was achieved. The synthesis involves construction of a cis-decalin ring by an intramolecular Diels-Alder reaction and construction of an all-trans-perhydrophenalene ring by an intramolecular Michael reaction as the key steps. Georg Thieme Verlag Stuttgart.
- Miyaoka, Hiroaki,Okubo, Yusuke
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Read Online
- Modifying the chemistry of the phosphole dienic system by α-vinylation
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1-Phenyl-2-vinyl-3,4-dimethylphosphole (4) was prepared from the corresponding 2-carboxaldehyde via a Wittig reaction. The reaction of its P-W(CO)5 complex 5 with [PhP-W(CO)5] selectively takes place at the vinyl double bond and give
- Ng, Kim Hong,Li, Yongxin,Ganguly, Rakesh,Mathey, Francois
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Read Online
- Asymmetric synthesis and absolute stereochemistry of a labdane-type diterpenoid isolated from the rhizomes of: Isodan yuennanensis
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The first synthesis of a labdane-type diterpenoid isolated from Isodon yuennanensis was achieved in fourteen steps from commercially available starting material, (+)-sclareolide. The synthesis features the Barton nitrite ester reaction to introduce an oxi
- Deng, Heping,Cao, Wei,Zhang, Zhijiang,Liu, Bo
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- Allylindation of 6-substituted 2-hydroxy-l-tetralones in aqueous and organic media. stereochemistry and competition studies
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A systematic investigation of the stereoselectivity associated with coupling reactions involving the allylindium reagent and 6-substituted 2-hydroxy-l-tetralones is presented. In each instance, the allylations were carried out in water, 50% aqueous THF, a
- Lobben, Paul C.,Paquette, Leo A.
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- SYNTHETIC AND STEREOCHEMICAL STUDIES RELATED TO TRANS-CLERODANE DITERPENOIDS AND CONGENERS
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Synthesis of a key trans-clerodane diterpenoid intermediate 6, which is also a degradation product of ilimaquinone, is described.In view of a discrepancy in our earlier work on correlation of the stereochemistry of ketoester (5), with that of avarol, the
- Sarma, Aluru S.,Gayen, Ashok K.
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- Novel reaction of methylenetriphenylphosphorane with epichlorohydrin leading to alkylidenecyclobutanols
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The reaction of methylenetriphenylphosphorane with epichlorohydrin followed by the addition of butyllithium and aldehydes in toluene afforded unusual four-membered cyclic alkylidenecyclobutanols.
- Okuma, Kentaro,Tsubakihara, Kimiko,Tanaka, Yuichiro,Koda, Gen,Ohta, Hiroshi
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Read Online
- Substituted dienes prepared from betulinic acid – Synthesis, cytotoxicity, mechanism of action, and pharmacological parameters
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A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22, 4.30, 4.33, 4.39 had IC50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC50 and almost complete inhibition at 5 × IC50. Interestingly, compound 4.39 at 5 × IC50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39, therefore 4.22 was the finally selected candidate for the development of anticancer drug.
- Frydrych, Ivo,Urban, Milan,?arek, Jan,Benická, Sandra,D?ubák, Petr,Gurská, Soňa,Hajdúch, Marián,Kotulová, Jana,Li?ková, Barbora,Olejníková, Denisa,Pokorny, Jan
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- Stable Singlet Carbenes as Organic Superbases
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A simple experimental procedure for scaling carbene Br?nsted basicity is described. The results highlight the strong basicity of pyrazol-4-ylidenes, a type of mesoionic carbene, also named cyclic-bentallenes (CBA). They are more basic (pKaH >42.7 in acetonitrile) than the popular proazaphosphatrane Verkade bases, and even the Schwesinger phosphazene superbase P4(tBu). The basicity of these compounds can readily be tuned, and they are accessible in multigram quantities. These results open new avenues for carbon centered superbases.
- Bertrand, Guy,Grotjahn, Douglas B.,Jazzar, Rodolphe,Junor, Glen P.,Vermersch, Fran?ois,Yazdani, Sima
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supporting information
p. 27253 - 27257
(2021/11/22)
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- Short enantioselective total synthesis of (+)-tofacitinib
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An enantioselective total synthesis of Tofacitinib (CP-690,550), a Janus tyrosine kinase (JAK3) specific inhibitor has been achieved from the readily available 4-piperidone. Proline catalysed hydroxylation is the key step for the synthesis of enantiopure 1-benzyl-4-methylpiperidin-3-ol.
- Mane, Kishor D.,Kamble, Rohit B.,Suryavanshi, Gurunath
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supporting information
(2021/02/20)
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- Synthesis of C-linked α-Gal and α-GalNAc-1′-hydroxyalkanes by way of C2 functionality transfer
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Inspired by reports of water sculpted Tn antigen (α-GalNAc-O-Ser/Thr) epitopes and our interest in producing metabolically more stable C-linked analogs of Tn, we explored the utility of C2 functionality on α-Gal-C-alkenes to deliver hydroxyl to the pendant alkenyl chain. Toward this end, a cyclic carbonate approach gave rise to a single C-linked α-Gal-1′(S)-hydroxyethane in 3 steps, and use of a 2-(hydroxyimino)galactoside cyclization transferred an oxygen to a pendant cis-substituted C-linked alkene affording the R-configuration at the newly formed stereocenter (7:1 dr). Reduction and acetylation of the resultant isoxazoline demonstrated this approach as a viable route to C-linked α-GalNAc-1′-hydroxyalkanes.
- Nolen, Ernest G.,Hornik, Ezra S.,Jeans, Kendra B.,Zhong, Weiyu,LaPaglia, Danielle M.
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supporting information
(2021/05/06)
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- Responsive organoboranes with dynamic conformation of octacyclophane-type scaffolds: synthesis, AIE and temperature-dependent dual emissions
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In the field of synthetic organic materials, there is still an urgent demand for new smart materials that show great potential in diverse applications. We herein describe a design strategy for the synthesis of luminescent organoboranes (M1,M2andM3) that f
- Chen, Pangkuan,Ji, Guangqian,Li, Quansong,Wang, Nan,Yin, Xiaodong,Zhang, Kai,Zhang, Niu
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supporting information
p. 13851 - 13859
(2021/10/20)
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- Nature of the Arsonium-Ylide Ph3As=CH2 and a Uranium(IV) Arsonium–Carbene Complex
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Treatment of [Ph3EMe][I] with [Na{N(SiMe3)2}] affords the ylides [Ph3E=CH2] (E=As, 1As; P, 1P). For 1As this overcomes prior difficulties in the synthesis of this classical arsonium-ylide that have hi
- Futcher, Harry J.,Liddle, Stephen T.,Seed, John A.,Sharpe, Helen R.,Wooles, Ashley J.
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p. 15870 - 15874
(2020/07/04)
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- Synthesis and evaluation of resveratrol derivatives as fetal hemoglobin inducers
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Resveratrol (RVT) derivatives (10a-i) were designed, synthesized, and evaluated for their potential as gamma-globin inducers in treating Sickle Cell Disease (SCD) symptoms. All compounds were able to release NO at different levels ranging from 0 to 26.3percent, while RVT did not demonstrate this effect. In vivo, the antinociceptive effect was characterized using an acetic acid-induced abdominal contortion model. All compounds exhibited different levels of protection, ranging from 5.9 to 37.3percent; the compound 10a was the most potent among the series. At concentrations between 3.13 and 12.5 μM, the derivative 10a resulted in a reduction of 41.1–64.3percent in the TNF-α levels in the supernatants of macrophages that were previously LPS-stimulated. This inhibitory effect was higher than that of RVT used as the control. In addition, the compound 10a and RVT induced double the production of the gamma-globin chains (γG + γA), compared to the vehicle, using CD34+ cells. Compound 10a also did not induce membrane perturbation and it was not mutagenic in the in vivo assay. Thus, compound 10a emerged as a new prototype of the gamma-globin-inducer group with additional analgesic and anti-inflammatory activities and proving to be a useful alternative to treat SCD symptoms.
- Andersen, Olaf Sparre,Barbieri, Karina Pereira,Bosquesi, Priscila Longhin,Carlos, Iracilda Zepone,Chelucci, Rafael Consolin,Costa, Fernando Ferreira,Dos Santos, Jean Leandro,Fernandes, Guilherme Felipe dos Santos,Lanaro, Carolina,Melchior, Aylime Castanho Bolognesi,Pavan, Aline Renata,Rusinova, Radda,de Souza, Cristiane Maria
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- CARBOCYCLIC DERIVATIVES AND CONJUGATED DERIVATIVES THEREOF, AND THEIR USE IN VACCINES
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The invention is in the field of vaccines and relates to oligomers having a selected degree of polymerization, obtained by connecting together a number of carbocyclic repeating units, and to conjugated derivatives thereof. The oligomers and conjugated derivatives thereof of the invention also have a selected degree of acetylation. The derivatives of the invention are useful for the preparation of immunogenic compositions, e.g. in the form of a vaccine.
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Page/Page column 42
(2020/09/30)
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- A unified, RCM anchored approach to spiro[4.5]decane-based sesquiterpenoids: Collective synthesis of (±)-α & β-vetispirenes, (±)-β-vetivone, (±)-agarospirol and (±)-hinesol
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Collective syntheses of five spiro[4.5]decane framework bearing sesquiterpenoids, namely, α & β-vetispirenes, β-vetivone, agarospirol and hinesol as well as formal synthesis of axenol and gleenol from a readily available precursor cyclohexanone-β-ketoester via the intermediacy of a versatile intermediate (2,10-dimethylspiro[4.5]dec-1-en-6-one) have been accomplished in a concise manner.
- Athe, Sudhakar,Ghosh, Subhash,Mehta, Goverdhan
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supporting information
p. 1570 - 1573
(2019/05/22)
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- INHIBITORS OF PLATELET FUNCTION AND METHODS FOR USE OF THE SAME
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Disclosed herein are small molecule inhibitors of platelet function, and methods of using the small molecules to treat diseases, such as platelet hemostasis and thrombosis. In particular, disclosed herein are compounds of Formula (I) and pharmaceutically acceptable salts thereof: wherein the substituents are as described.
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Paragraph 0075; 0079
(2019/11/12)
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- MCPBA-Mediated Intramolecular Oxidative Annulation of ortho-Crotyl or Cinnamyl Arylaldehydes: Synthesis of Benzofused Five-, Six-, and Seven-Membered Oxacycles
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mCPBA-mediated intramolecular oxidative annulation of ortho-crotyl or cinnamyl arylaldehydes provides chroman, coumaran, isochroman, and tetrahydrobenzo[c]oxepine under different reaction conditions. This research investigates the reaction conditions for facile and efficient transformation.
- Chang, Meng-Yang,Hsiao, Yu-Ting,Lai, Kai-Hsiang
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p. 14110 - 14119
(2018/11/21)
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- Stereoselective synthesis of peracetylated (?)-gloeosporiol via acid catalysed intramolecular etherification
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A simple and an efficient strategy have been developed for the stereoselective synthesis of peracetylated (?)-gloeosporiol by acid catalysed cyclisation from the commercially available starting materials.
- Dorigundla, Aravind Reddy,Gurrapu, Raju,Batchu, Venkateswara Rao
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supporting information
p. 563 - 565
(2017/01/16)
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- Click functionalization of a dibenzocyclooctyne-containing conjugated polyimine
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A conjugated poly(phenyl-co-dibenzocyclooctyne) Schiff-base polymer, prepared through polycondensation of dibenzocyclooctyne bisamine (DIBO-(NH2)2) with bis(hexadecyloxy)phenyldialdehyde, is reported. The resulting polymer, which has
- Kardelis, Vladimir,Chadwick, Ryan C.,Adronov, Alex
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supporting information
p. 945 - 949
(2016/01/20)
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- A transition-metal-free Heck-type reaction between alkenes and alkyl iodides enabled by light in water
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A transition-metal-free coupling protocol between various alkenes and non-activated alkyl iodides has been developed by using photoenergy in water for the first time. Under UV irradiation and basic aqueous conditions, various alkenes efficiently couple with a wide range of non-activated alkyl iodides. A tentative mechanism, which involves an atom transfer radical addition process, for the coupling is proposed.
- Liu, Wenbo,Li, Lu,Chen, Zhengwang,Li, Chao-Jun
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p. 6170 - 6174
(2015/06/08)
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- A divergent approach for the synthesis of some polyhydroxy pyrrolidines and piperidines from ribosylamine
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A simple and efficient synthesis of 1,4-dideoxy-1,4-imino-d-ribitol, 1,4-dideoxy-1,4-imino-l-lyxitol, N-benzyl derivative of d-ribitol, 3,4,5-trihydroxy-piperidine, l-4-epi-isofagomine and d-3-epi-isofagomine, which are glycosidase inhibitors has been described from the commercially available d-ribose as a starting material.
- Chirke, Sahadev S.,Rajender, Anugula,Rao, Batchu Venkateswara
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p. 103 - 109
(2014/01/06)
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- Total synthesis of dixiamycin B by electrochemical oxidation
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N-N-linked dimeric indole alkaloids represent an unexplored class of natural products for which chemical synthesis has no practical solution. To meet this challenge, an electrochemical oxidative dimerization method was developed, which was applied as the pivotal step of the first total synthesis of dixiamycin B. This method is also general for N-N dimerization of substituted carbazoles and β-carbolines, providing entry into seldom explored chemical space.
- Rosen, Brandon R.,Werner, Erik W.,O'Brien, Alexander G.,Baran, Phil S.
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supporting information
p. 5571 - 5574
(2014/05/06)
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- A stereoselective total synthesis of decarestrictine I
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A convergent and stereoselective total synthesis of decarestrictine I, a polyketide natural product, is described. Both acid and alcohol fragments were prepared from the readily available L-malic acid via Still-Gennari olefination and Sharpless asymmetric epoxidation. The Steglich esterification and ring-closing metathesis (RCM) are employed to combine both acid and alcohol fragments. Copyright
- Yadav, Jhillu Singh,Venkatesh, Miriyal,Kumar, Alleni Suman,Reddy, Poli Adi Narayana,Reddy, Basi V. Subba,Prasad, Attaluri R.
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p. 830 - 838
(2014/07/07)
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- Synthesis of dibenzoheteropines of group 13-16 elements via ring-closing metathesis
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The ring-closing metathesis (RCM) of bis(2-vinylphenyl)silanes in the presence of the second-generation Hoveyda-Grubbs catalyst in toluene at 100 C afforded dibenzo[b,f]silepines in excellent yields. Other dibenzoheteropines of group 13-16 elements were also prepared via the RCM of the corresponding heteroatom-tethered dienes.
- Matsuda, Takanori,Sato, Shinya
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p. 3329 - 3335
(2013/06/26)
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- Wittig-olefination via an yttrium-coordinated betaine
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We report the synthesis of an yttrium phosphonium methylide complex and its reaction with benzophenone to form an excedingly rare hydrocarbon soluble metal-coordinated betaine. While this reaction models the C-C σ-bond formation step of the Wittig reaction under salt-conditions, addition of Ph 3PO to the betaine complex results in formation of 1,1-diphenylethene.
- Crimmin, Mark R.,White, Andrew J. P.
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supporting information; experimental part
p. 1745 - 1747
(2012/03/09)
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- Formal total synthesis of aspergillides A and B
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The formal total synthesis of the cytotoxic 14-membered macrolides, aspergillides A and B is described. A combination of a chiron approach and an asymmetric synthesis is adopted for the synthesis of the target macrolides. The required 2,6-syn and 2,6-anti
- Sharma, Gangavaram V.M.,Manohar, Vennampalli
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experimental part
p. 252 - 263
(2012/06/15)
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- Highly stereoselective synthesis of novel trans-thiophenylene-silylene- vinylene-arylene molecular and macromolecular compounds
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Novel stereoregular molecular compounds 8-13 containing thiophenylene-silylene-vinylene-phenylene units have been synthesised via highly effective silylative coupling of styrene and 1,4-divinylbenzene (7) with respective vinylsilylthiophenes (3, 4) and bis(vinylsilyl)thiophenes (5, 6) catalyzed by RuHClCO(PCy3)2. Respective copolymers (14, 15) were produced via silylative copolycondensation of 5 and 6 with 7. All products were isolated and characterised by NMR, MS, HRMS and two of them 10 and 11 by X-ray method. Catalytic study as well as stoichiometric reactions of Ru-H (1) with 2-(vinylsilyl)thiophene (3) and Ru-Si (16) with styrene confirmed the mechanism of the silylative coupling olefins with vinylsilicon compounds.
- Ludwiczak, Monika,Majchrzak, Mariusz,Marciniec, Bogdan,Kubicki, MacIej
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experimental part
p. 1456 - 1464
(2011/05/09)
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- Domino Friedel-crafts-type cyclizations of difluoroalkenes promoted by the α-cation-stabilizing effect of fluorine: An efficient method for synthesizing angular PAHs
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In order to synthesize polycyclic aromatic hydrocarbons with nonlinear arrangements (angular PAHs), acid-promoted domino cyclizations of 1,1-difluoroalk-1-enes and 1,1-difluoroalka-1,3-dienes were studied. 1,1-Difluoroalkenes, each bearing two aryl substituents, were regioselectively protonated with FSO3H·SbF5 to generate fluorine-stabilized carbocations, which readily underwent domino Friedel-Crafts-type cyclizations to give carbocycles based on 6/n/m/6 ring systems (n,m=5-7) in good to high yields. Protonation of 1,1-difluoroalka-1,3- dienes took place at their electron-rich methylene (CH2) carbon atoms in the presence of milder acids such as camphorsulfonic acid and trifluoromethanesulfonic acid. Domino cyclizations of the resulting fluorine-stabilized allylic carbocations afford carbocycles based on 6/6/6/6 or 6/6/5/6 ring systems in high yields.
- Fuchibe, Kohei,Jyono, Hideharu,Fujiwara, Masaki,Kudo, Takao,Yokota, Misaki,Ichikawa, Junji
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experimental part
p. 12175 - 12185
(2011/12/01)
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- A highly convergent approach toward (-)-brevenal
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Progress toward a highly convergent, asymmetric synthesis of brevenal is reported. Construction of the AB-ring and E-ring cyclic ether fragments was achieved through asymmetric alkylation/ring-closing metathesis strategies. A Horner-Wadsworth-Emmons olefination was used in a key bond-forming step to couple the advanced cyclic fragments and enable rapid access to the AB-E ring system.
- Crimmins, Michael T.,Shamszad, Mariam,Mattson, Anita E.
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supporting information; experimental part
p. 2614 - 2617
(2010/08/22)
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- Halo-Wittig- and zirconium-promoted synthesis of conjugated metalloporphyrin dimers
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The synthesis and spectroscopic studies of metalloporphyrin dimers having 1,3-butadiyne linker attached to the beta pyrrolic positions of the linked porphyrins are reported. Bromoethenyl metalloporphyrins were synthesized by zirconocene-promoted bromomethylenation of beta formyl metalloporphyrins. Bromoethenyl metalloporphyrins were dehydrohalogenated by potassium tertbutoxide to give beta ethynyl or 2-ethynyl metalloporphyrins. It is the first documented example of zirconocene-promoted bromomethylenation of beta formyl metalloporphyrins. Bromoethenyl metalloporphyrins were also synthesized by halo-Wittig route. 2-ethynyl metalloporphyrins were self dimerized to give metalloporphyrin dimers having 1,3-butadiyne linking bridge. FTIR, Raman spectroscopy, UV-visible, elemental analysis, 1H NMR and mass spectrometry were used to characterize the compounds. Copyright
- Yaseen, Muhammad,Ali, Mukhtar,Munawar, Munawar Ali,Salim, Muhammad,Najeebullah, Muhammad,Khokhar, Irshad,Sayyad, Muhammad H.
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experimental part
p. 298 - 304
(2010/11/21)
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- Synthesis of the macrocyclic core of iriomoteolide-1a
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The fully functionalized macrocyclic core of the marine natural product iriomoteolide-1a has been successfully constructed in a convergent and enantioselective manner.
- Li, Shuo,Chen, Zheng,Xu, Zhengshuang,Ye, Tao
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supporting information; experimental part
p. 4773 - 4775
(2010/09/16)
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- A total synthesis of natural Rhizobialide
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Natural butanolide Rhizobialide was synthesized for the first time in enantiopure form with the stereogenic center derived from glutamic acid.
- Guan, Jing,Zou, Yang,Gao, Po,Wu, Yikang,Yue, Zhengyu
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experimental part
p. 1613 - 1617
(2011/07/08)
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- Total synthesis and determination of relative and absolute configuration of multiplolide A
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(Chemical Equation Presented) A flexible approach for total syntheses of possible multiplolide A diastereomers establishing the relative and absolute configuration is documented. The adopted strategy features ring-closing metathesis (RCM) as the key reaction and screening of a set of substrates for the feasibility of RCM in general and for the requisite E-configuration of ring olefin in particular. Selective protecting groups manipulation prior to the assembly of the central macrocyclic core was instrumental in installing the epoxide functionality on a fully deprotected nonenolide at the end of the synthesis.
- Ramana,Khaladkar, Tushar P.,Chatterjee, Soumitra,Gurjar, Mukund K.
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p. 3817 - 3822
(2008/09/19)
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- Homodinuclear ruthenium catalysts for dimer ring-closing metathesis
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(Chemical Equation Presented) Two ring or not to ring: Novel diruthenium olefin metathesis catalysts show a tendency to avoid oligomerization and favor cyclic dimerization when the distances between the ruthenium centers and between the diene extremities match (see scheme).
- Tzur, Eyal,Ben-Asuly, Amos,Diesendruck, Charles E.,Goldberg, Israel,Lemcoff, N. Gabriel
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supporting information; experimental part
p. 6422 - 6425
(2009/03/11)
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- The asymmetric total synthesis of (+)-cytotrienin A, an ansamycin-type anticancer drug
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(Chemical Equation Presented) A star-studded lineup: (+)-Cytotrienin A was the target of an asymmetric total synthesis featuring an enantioselective aldol reaction, α-aminoxylation, deoxygenation, and a ring-closing metathesis to form the 21-membered macrolactam. This first total synthesis confirms the relative and absolute confguration of the molecule.
- Hayashi, Yujiro,Shoji, Mitsuru,Ishikawa, Hayato,Yamaguchi, Junichiro,Tamura, Tomohiro,Imai, Hiroki,Nishigaya, Yosuke,Takabe, Kenichi,Kakeya, Hideaki,Osada, Hiroyuki
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supporting information; experimental part
p. 6657 - 6660
(2009/03/12)
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- Total synthesis of (-)-brevenal: A concise synthetic entry to the pentacyclic polyether core
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(Chemical Equation Presented) Total synthesis of (-)-brevenal, a novel marine polycyclic ether natural product, is described. Highly efficient and scalable entries to the AB-ring exo-olefin and the DE-ring enol phosphate and a rapid construction of the C-
- Ebine, Makoto,Fuwa, Haruhiko,Sasaki, Makoto
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supporting information; experimental part
p. 2275 - 2278
(2009/05/11)
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- Process for total synthesis of pladienolide B and pladienolide D
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[Problems to be Solved] To provide an effective process for total synthesis of pladienolide B and pladienolide D having excellent anti-tumor activity and to provide useful intermediates in the above-described process. [Measure for Solving the Problem] A process for producing a compound represented by Formula (11): wherein P1, P7, P8, P9 and R1 are the same as defined below, characterized by including reacting a compound represented by Formula (12): wherein P7 means a hydrogen atom or a protecting group for hydroxy group; R1 means a hydrogen atom or a hydroxy group, with a compound represented by Formula (13): wherein P1 means a hydrogen atom or a protecting group for hydroxy group; P8 means a hydrogen atom, an acetyl group or a protecting group for hydroxy group; P9 means a hydrogen atom or a protecting group for hydroxy group; or P8 and P9 may form together a group represented by a formula: wherein R5 means a phenyl group which may have a substituent, in the presence of a catalyst.
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Page/Page column 26; 30
(2010/11/29)
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- 12 MEMBERED-RING MACROLACTAM DERIVATIVES
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There provided a 12-membered-ring macrolactam derivative having antitumor activity: A compound represented by Formula (1) or a salt thereof. In this Formula, R1 is a hydrogen atom, a C1-6 alkyl group, a C1-6 alkylcarbonyl
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Page/Page column 27-28; 39-40
(2009/01/24)
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- Luminescence system, method of luminescence, and chemical substance for luminescence
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An object of the present invention is to provide, inexpensively and safely, a luminescence system, a method of luminescence, and a luminescent substance based on a novel luminescence mechanism that luminesces at high efficiency. The present invention rela
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Page/Page column 11
(2008/06/13)
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- JNK inhibitors
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The present invention provides novel compounds of formula I and their use in the inhibition of c-Jun N-terminal kinases. The present invention further provides the use of these compounds in medicine, in particular in the prevention and/or treatment of neu
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Page/Page column 77
(2010/11/25)
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- Total synthesis of the potent antitumor macrolides pladienolide B and D
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Getting cross: The total syntheses of two pladienolides (see picture), which have prominent antitumor activity based on a unique mechanism of action, have been accomplished, and their absolute configurations were verified. The 12-membered aliphatic macrolide structure was formed by ring-closing metathesis, and the side-chain moiety was coupled to the macrolide by Julia-Kocienski olefination or cross-metathesis. (Chemical Equation Presented).
- Kanada, Regina M.,Itoh, Daisuke,Nagai, Mitsuo,Niijima, Jun,Asai, Naoki,Mizui, Yoshiharu,Abe, Shinya,Kotake, Yoshihiko
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p. 4350 - 4355
(2008/03/12)
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- Stereoselective synthesis of the polyketide chain of nagahamide A
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A carbohydrate based approach for the enantioselective synthesis of the polyketide acid unit present in nagahamide A has been reported. Reductive ring opening of a chiral cyclopropane ketone group to enantioselectively install the methyl and propyl groups
- Mohapatra, Debendra K.,Chaudhuri, Siddhartha Ray,Sahoo, Gokarneswar,Gurjar, Mukund K.
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p. 2609 - 2616
(2007/10/03)
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- PHARMACEUTICAL COMPOUNDS
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The invention provides a compound of the formula (I) or a salt, solvate, tautomer or N-oxide thereof for use in the treatment or prophylaxis of a disease state or condition mediated by protein kinase A and/or protein kinase B, wherein the ring Q is a benzene ring; J2-J1 is N=CR7 or R1aN-CO; G is OH or NR5R6; E is CONR7, NR7CO, C(R8)=C(R8) or (X)m(CR8R8a)n where X is O, S or NR7; provided that when J2-J1 is R1aN-CO, E is other than NR7CO; m and n are each 0 or 1, where m + n = 1 or 2; A is a bond and R4 and R4a are absent, or A is a saturated optionally substituted C1-7 hydrocarbon linker group having a maximum chain length of 5 atoms extending between E and G, one carbon atom in the linker group A being optionally replaced by O or N; R1,Rla, R2, and R3 are each H; halogen; C1-6 hydrocarbyl optionally substituted by halogen, OH or C1-2 alkoxy; CN; CONHR8; NH2; NHCOR10 or NHCONHR10; R4 is H or C1-4 alkyl; R4a is H, C1-4 alkyl or a group R9; R5 and R6 are each selected from H, R9 and C1-4 hydrocarbyl optionally substituted by halogen, C1-2 alkoxy or R9;or NR5R6 forms a saturated 4-7 membered monocyclic heterocyclic group; R7 is H or C1-4 alkyl; R8 and R8a each H or saturated C1-4 hydrocarbyl optionally substituted by fluorine; R9is a monocyclic or bicyclic carbocyclic or heterocyclic group containing up to 3 ring heteroatoms selected from N, O and S; or R4, R4a and A together form a saturated monocyclic 4-7 membered heterocycle; or NR5R6, R4 and A form a saturated 4-7 membered monocyclic heterocycle; or R4,together with R7 or R8 and A and E form a 4-7 membered saturated monocyclic heterocycle; or NR5R6 and R7 or R8 together with A and E form a 4-7 membered saturated monocyclic heterocycle; and R10 is optionally substituted phenyl or benzyl.
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Page/Page column 145
(2010/11/30)
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- Enantiospecific total syntheses of (-)-valeranone
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Two convenient methodologies have been described for the enantiospecific synthesis of (-)-valeranone 1. The hydrindanone 12, obtained from the readily and abundantly available monoterpene (R)-carvone, has been converted into the ketoaldehyde 16 via the alkene 15b. In another direction the lactone 18, obtained from the hydrindanone 12, has been elaborated into the ketoaldehyde 16 employing two methodologies. Intramolecular aldol condensation followed by hydrogenation transformed the ketoaldehyde 16 into (-)-valeranone 1.
- Srikrishna,Viswajanani,Dinesh
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p. 1265 - 1274
(2007/10/03)
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- First synthesis and structural elucidation of (-)-presphaerene
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The first total synthesis of (-)-presphaerene (1) was achieved from (R)-glyceraldehyde 9 in 19 steps, demonstrating the novel "folding and allylic strain-controlled" intramolecular ester enolate S N2′ alkylation strategy could be extended to the stereoselective synthesis of cyclopentanoid natural products. The present study also established the relative and absolute stereochemistry of 1, and the absolute structures of co-occurring sphaeroanes from the red alga Sphaerococcus coronopifolius.
- Lee, Jongkook,Hong, Jiyong
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p. 6433 - 6440
(2007/10/03)
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- Can C-H ··· C(π) bonding be classified as hydrogen bonding? A systematic investigation of C-H ··· C(π) bonding to cyclopentadienyl anions
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The following ammonium and phosphonium cyclopentadienide complexes have been prepared, crystallized and investigated structurally: [Cp]-[Et4N]+, [Cp]-[Et4P]+, [Cp]-[Ph3/sub
- Harder
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p. 1852 - 1861
(2007/10/03)
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- Acylnitrene route to vicinal amino alcohols. Application to the synthesis of (-)-bestatin and analogues
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Bestatin, valinoctin A, and microginin are naturally occurring small peptides containing a nonproteinogenic α-hydroxy-α-amino acid at the N-terminus of the peptide chain. We report here our development of a general method for the synthesis of α-hydroxy-β-amino acids and exemplify this with a synthesis of (-)-bestatin and analogues. Our synthesis utilizes an intramolecular acylnitrene-mediated aziridination to generate a key bicyclic aziridine in excellent yield and stereoselectivity. This bicyclic aziridine can be opened with a number of organometallic reagents to provide a series of substituted oxazolidinones. The oxazolidinones are readily converted to bestatin and a series of bestatin analogues. As part of this approach, we have developed a new method for the synthesis of azidoformates. We have also demonstrated that oxazolidinones can be selectively hydrolyzed in the presence of peptide bonds. This acylnitrene route to bestatin should prove useful for the synthesis of a variety of analogues of bestatin as well as other α-hydroxy-β-amino acids and their corresponding peptides.
- Bergmeier, Stephen C.,Stanchina, Dionne M.
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p. 2852 - 2859
(2007/10/03)
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- Preparation of symmetrical divinyl tellurides via an ylidation reaction
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Symmetrical divinyl tellurides are prepared by sequential reaction of bis-(triphenylmethyl phosphonium) halotellurate with base or by the reaction of triphenylmethylidene phosphoranes with TeCl4, followed by aldehydes. The products are converted to E-α,β-unsaturated aldehydes by treatment with n-BuLi and DMF.
- Silveira, Claudio C.,Perin, Gelson,Boeck, Paula,Braga, Antonio L.,Petragnani, Nicola
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- D-Galactofuranosylphosphonates. First Synthesis of UDP-C-D-galactofuranose
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The chemical synthesis of two phosphono analogues of D-galactofuranosyl phosphate was performed. The natural phosphate seemed to be too labile to allow the chemical synthesis of UDP-Galf, these C-galactofuranosides are stable pharmacophores, and the α-phosphono analogue has been easily converted into UDP-C-Galf. UDP-C-Galf was tested as a competitive inhibitor of UDP-galactopyranose mutase and showed inhibition of Galf formation. Thus, it is of potential interest as an antimycobacterial agent; as an active molecule against Trypanosoma cruzi, the causative agent of South American trypanosomiasis (Chagas' disease), and as a stable analogue for use in UDP-galactopyranose mutase crystallization studies.
- Kovensky, Jose,McNeil, Michael,Sinay, Pierre
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p. 6202 - 6205
(2007/10/03)
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