- Concise synthesis of acetal-protected syn 1,3-diols by a tandem hemiacetal formation/Tsuji-Trost reaction
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Designed, developed, and applied: A novel domino sequence was used for the rapid assembly of acetal-protected syn 1,3-diols. The convergent synthesis of a polyol fragment of the macrolide antibiotic RK-397 demonstrates that this method is suitable for the rapid and stereoselective preparation of polyketide-type diol motifs.
- Wang, Liang,Menche, Dirk
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Read Online
- Computationally guided discovery of a reactive, hydrophilic: Trans -5-oxocene dienophile for bioorthogonal labeling
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The use of organic chemistry principles and prediction techniques has enabled the development of new bioorthogonal reactions. As this "toolbox" expands to include new reaction manifolds and orthogonal reaction pairings, the continued development of existing reactions remains an important objective. This is particularly important in cellular imaging, where non-specific background fluorescence has been linked to the hydrophobicity of the bioorthogonal moiety. Here we report that trans-5-oxocene (oxoTCO) displays enhanced reactivity and hydrophilicity compared to trans-cyclooctene (TCO) in the tetrazine ligation reaction. Aided by ab initio calculations we show that the insertion of a single oxygen atom into the trans-cyclooctene (TCO) ring system is sufficient to impart aqueous solubility and also results in significant rate acceleration by increasing angle strain. We demonstrate the rapid and quantitative cycloaddition of oxoTCO using a water-soluble tetrazine derivative and a protein substrate containing a site-specific genetically encoded tetrazine moiety both in vitro and in vivo. We anticipate that oxoTCO will find use in studies where hydrophilicity and fast bioconjugation kinetics are paramount.
- Lambert, William D.,Scinto, Samuel L.,Dmitrenko, Olga,Boyd, Samantha J.,Magboo, Ronald,Mehl, Ryan A.,Chin, Jason W.,Fox, Joseph M.,Wallace, Stephen
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Read Online
- Synthesis of (R)-(-)-argentilactone
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A synthesis of (R)-(-)-argentilactone is reported starting from the (S)-enantiomer of glycidol. The synthesis is based on ring closing metathesis of the acrylic ester of (R)-1-O-(tert-butyldiphenylsilyl)-4-penten-1,2-diol 4.
- Hansen, Trond Vidar
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Read Online
- Total Synthesis of (R)-Argentilactone and (R)-Goniothalamin Using a Free-Radical Photoredox Approach to α,β-Unsaturated δ-Lactones
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α,β-Unsaturated δ-lactones are structural motifs found in diverse pharmacologically active natural products. In fact, the unsaturated lactone is often responsible for the biological activity. Herein, we report a new approach for the syntheses of (R)-argentilactone and (R)- goniothalamin based on a photoredox intermolecular iodolactonization mediated by a photoredox process. This new approach, already employed in our research group, stands as a new methodology to achieve several natural products containing α,β-Unsaturated δ-lactones.
- Fuentes-Pantoja, Francisco J.,Cordero-Vargas, Alejandro
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supporting information
p. 4433 - 4439
(2021/08/20)
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- CD73 INHIBITORS
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The present invention provides 5-[5]-[2-cycloa Ikyl ]-6-pyridazin-3-yl ]- IH-pyrimidine-2,4-dione compounds, or pharmaceutically acceptable salts thereof, that inhibit the activity of CD73 and are useful in treating cancer. (Formula (I))
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Page/Page column 42
(2019/09/18)
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- Development of Hybrid Phospholipid Mimics as Effective Agonists for Liver Receptor Homologue-1
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The orphan nuclear receptor Liver Receptor Homologue-1 (LRH-1) is an emerging drug target for metabolic disorders. The most effective known LRH-1 modulators are phospholipids or synthetic hexahydropentalene compounds. While both classes have micromolar ef
- Flynn, Autumn R.,Mays, Suzanne G.,Ortlund, Eric A.,Jui, Nathan T.
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supporting information
p. 1051 - 1056
(2018/09/21)
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- COMPOUNDS AND METHODS FOR THE TREATMENT OF PARASITIC DISEASES
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Provided herein are compounds useful for the treatment of various parasitic diseases. These compounds, as well as pharmaceutically acceptable salts thereof may be formulated in pharmaceutical compostions, veterinary compositions and may be used in methods
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Page/Page column 81; 82
(2018/10/19)
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- Synthesis of Vicinal Dichlorides via Activation of Aliphatic Terminal Epoxides with Triphosgene and Pyridine
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Herein we report a novel synthetic reaction to convert unactivated terminal aliphatic epoxide to alkyl vicinal dichloride based on triphosgene-pyridine activation. Our methodology is operationally simple and readily tolerated by a broad of scope of substrates as well as protecting groups. Furthermore, these mild conditions generally yield clean reaction mixtures that are free of byproducts upon aqueous workup.
- Cleveland, Alexander H.,Fronczek, Frank R.,Kartika, Rendy
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p. 3367 - 3377
(2018/03/26)
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- Design, synthesis, and cytotoxicity of stabilized mycolactone analogs
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On exposure to visible light, mycolactone A/B, the causative toxin of Buruli ulcer, rearranges to a mixture of four photo-mycolactones apparently via a rare photochemically-induced [4πs?+?2πa] cycloaddition. In
- Babu, Vaddela Sudheer,Zhou, Ya,Kishi, Yoshito
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supporting information
p. 1274 - 1277
(2017/06/21)
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- Antimalarial diterpenoid dimers of a new carbon skeleton from Aphanamixis grandifolia
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Chemical investigation into the minor constituents of Aphanamixis grandifolia yielded three new diterpenoid dimers, aphadilactones E-G (1-3) featuring a new carbon skeleton. Their structures and absolute configurations were fully established by comprehensive spectroscopic data analysis and ECD calculation. Discovery of another two new dimers (4 and 5) suggested the structure of recently reported aphanamene A to be re-investigated. Compounds 1-5 showed moderate antimalarial activities with low micromolar IC50 values.
- Zhang, Hua,Liu, Jia,Gan, Li-She,Dalal, Seema,Cassera, Maria B.,Yue, Jian-Min
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supporting information
p. 957 - 962
(2016/01/15)
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- Stereoselective total synthesis and stereochemistry confirmation of photo-mycolactones
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With use of the LiTMP-induced Hodgson cyclopropanation of an epoxide-olefin to a bicyclo[3.1.0]hexanol as the key step, a stereoselective total synthesis of photo-mycolactones was achieved. Each of the four diastereomeric epoxide-olefins, selectively prep
- Li, Xiaoyong,Babu, Vaddela Sudheer,Kishi, Yoshito
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supporting information
p. 3220 - 3224
(2015/05/27)
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- Total Synthesis, Stereochemical Revision, and Biological Reassessment of MandelalideA: Chemical Mimicry of Intrafamily Relationships
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MandelalideA and three congeners had recently been isolated as the supposedly highly cytotoxic principles of an ascidian collected off the South African coastline. Since these compounds are hardly available from the natural source, a concise synthesis rou
- Willwacher, Jens,Heggen, Berit,Wirtz, Conny,Thiel, Walter,Fürstner, Alois
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supporting information
p. 10416 - 10430
(2015/07/07)
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- ARYL FUSED LACTAMS AS EZH2 MODULATORS
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This invention relates to compounds of Formula (I) in which R1, R2, R3, R4, X and Z are as defined herein, and the pharmaceutically acceptable salts thereof, to pharmaceutical compositions comprising such compounds and salts, and to methods of using such compounds, salts and compositions for the treatment of abnormal cell growth, including cancer.
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Page/Page column 98; 99
(2016/04/19)
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- Catalysis-based total synthesis of putative mandelalide A
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A concise synthesis of the putative structure assigned to the highly cytotoxic marine macrolide mandelalide A (1) is disclosed. Specifically, an iridium-catalyzed two-directional Krische allylation and a cobalt-catalyzed carbonylative epoxide opening served as convenient entry points for the preparation of the major building blocks. The final stages feature the first implementation of terminal-acetylene metathesis into natural product synthesis, which is remarkable as this class of substrates was beyond reach until very recently; key to success was the use of the highly selective molybdenum alkylidyne complex 42 as the catalyst. Although the constitution and stereochemistry of the synthetic samples are unambiguous, the spectra of 1 as well as of 11-epi-1 deviate from those of the natural product, which implies a subtle but deep-seated error in the original structure assignment. Bitter and sweet: The synthesis of the proposed structure of the cytotoxic macrolide mandelalide A reiterates the notion that structure elucidation of architecturally complex natural products is not always reliable. From the chemical viewpoint, the chosen route attests to the power of (transition) metals as catalysts for stereoselective synthesis. Most notable is the first application of terminal-acetylene metathesis to natural product chemistry.
- Willwacher, Jens,Fuerstner, Alois
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supporting information
p. 4217 - 4221
(2014/05/06)
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- Coibacins a and b: Total synthesis and stereochemical revision
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The interface between synthetic organic chemistry and natural products was explored in order to unravel the structure of coibacin A, a metabolite isolated from the marine cyanobacterium cf. Oscillatoria sp. that exhibits selective antileishmanial activity and potent antiinflammatory properties. Our synthetic plan focused on a convergent strategy that allows rapid access to the desired target by coupling of three key fragments involving E-selective Wittig and modified Julia olefinations. CD measurements and comparative HPLC analyses of the natural product and four synthetic stereoisomers led to determination of its absolute configuration, thus correcting the original assignment at C-5 and unambiguously establishing those at C-16 and C-18. Additionally, we synthesized coibacin B on the basis of the assignment of configuration for coibacin A.
- Carneiro, Vania M. T.,Avila, Carolina M.,Balunas, Marcy J.,Gerwick, William H.,Pilli, Ronaldo A.
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p. 630 - 642
(2014/04/03)
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- Aphadilactones a-d, four diterpenoid dimers with dgat inhibitory and antimalarial activities from a meliaceae plant
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Aphadilactones A-D (1-4), four diastereoisomers possessing an unprecedented carbon skeleton, were isolated from the Meliaceae plant Aphanamixis grandifolia. Their challenging structures and absolute configurations were determined by a combination of spectroscopic data, chemical degradation, fragment synthesis, experimental CD spectra, and ECD calculations. Aphadilactone C (3) with the 5S,11S,5'S,11'S configuration showed potent and selective inhibition against the diacylglycerol O-acyltransferase-1 (DGAT- 1) enzyme (IC50 = 0.46 ± 0.09 μM, selectivity index > 217) and is the strongest natural DGAT-1 inhibitor discovered to date. In addition, compounds 1-4 showed significant antimalarial activities with IC50 values of 190 ± 60, 1350 ± 150, 170 ± 10, and 120 ± 50 nM, respectively.
- Liu, Jia,He, Xiu-Feng,Wang, Gai-Hong,Merino, Emilio F.,Yang, Sheng-Ping,Zhu, Rong-Xiu,Gan, Li-She,Zhang, Hua,Cassera, Maria B.,Wang, He-Yao,Kingston, David G. I.,Yue, Jian-Min
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p. 599 - 607
(2014/04/03)
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- Synthetic studies on polymaxenolides: Model studies for constructing dihydropyran portion and synthesis of lower portion
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With a goal of the total synthesis of polymaxenolide, the first hybrid marine natural product, the model studies for constructing the dihydropyran portion based on the originally proposed biosynthesis (C-C bond formation followed by dehydrative cyclization) and the synthesis of the lower portion (the C1-C3, C7-C17 portion) based on an iodide-induced Morita-Baylis-Hillman type reaction (a three-component assembly) followed by Suzuki-Miyaura cross-coupling are described.
- Matsuda, Yutaka,Kato, Masaya,Kawaguchi, Tomonori,Koyama, Takayuki,Saikawa, Yoko,Nakata, Masaya
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p. 1154 - 1168
(2014/02/14)
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- ARYL AND HETEROARYL FUSED LACTAMS
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This invention relates to compounds of general formula (I) in which R1, R2, U, V, L, M, R5, m, X, Y and Z are as defined herein, and the pharmaceutically acceptable salts thereof, to pharmaceutical compositions comprising such compounds and salts, and to methods of using such compounds, salts and compositions for the treatment of abnormal cell growth, including cancer.
- -
-
Paragraph 0838; 0847; 0848
(2014/07/08)
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- Synthesis of phosphonoglycine backbone units for the development of phosphono peptide nucleic acids
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A series of phosphono-modified backbone mimics based on achiral and chiral N-(dihydroxypropyl)glycine units were obtained by sequential addition of phosphonate and nucleobase moieties to suitably protected dihydroxypropylamines. Simple synthetic strategies enabled the preparation of various target derivatives that will be useful as building blocks for the preparation of new synthetic polymers containing a phosphonate internucleotide linkage in place of the standard phosphodiester bond. Copyright
- Doboszewski, Bogdan,Groaz, Elisabetta,Herdewijn, Piet
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p. 4804 - 4815
(2013/08/23)
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- Catalytic synthesis of enantiopure mixed diacylglycerols-synthesis of a major M. tuberculosis phospholipid and platelet activating factor
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An efficient catalytic one-pot synthesis of TBDMS-protected diacylglycerols has been developed, starting from enantiopure glycidol. Subsequent migration-free deprotection leads to stereo- and regiochemically pure diacylglycerols. This novel strategy has been applied to the synthesis of a major Mycobacterium tuberculosis phospholipid, its desmethyl analogue, and platelet activating factor.
- Fodran, Peter,Minnaard, Adriaan J.
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supporting information
p. 6919 - 6928
(2013/10/08)
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- NUCLEOSIDE ANALOG OR SALT THEREOF, OLIGONUCLEOTIDE ANALOG, GENE EXPRESSION INHIBITOR, AND NUCLEIC-ACID PROBE FOR DETECTING GENE
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A nucleoside analog and a salt thereof represented by any of the general formulae (1) to (10) below: wherein R1, R2, and R3 are the same or different groups, and each of the R1, R2 and R3 i
- -
-
Paragraph 0046; 0047
(2013/10/22)
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- A bidirectional SE′ strategy for 1,5- syn and 1,5- anti stereocontrol toward the synthesis of complex polyols
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Studies report a bidirectional SE′ strategy applicable for the stereocontrolled synthesis of nonracemic 1,5-syn and 1,5-anti diols and their derivatives. Nonracemic 1,3,2-diazaborolidine auxiliaries are incorporated by chemoselective tin-boron exchange to provide reactive allylic boranes. The convergent pathway utilizes sequential reactions with two aldehydes producing stereochemical outcomes from cyclic, closed, and open transition state preferences, respectively. Synthesis of fragment 16 of peloruside A is accomplished in four steps from readily available aldehydes 9 and 13.
- Williams, David R.,Claeboe, Christopher D.,Liang, Bo,Zorn, Nicolas,Chow, Nicholas S. C.
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scheme or table
p. 3866 - 3869
(2012/09/22)
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- Total synthesis of (-)-goniotrionin
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A stereoselective total synthesis of the reported structure of goniotrionin (4) has been accomplished. The key steps involved the opening of a chiral epoxide, a highly diastereoselective Mukaiyama aerobic oxidative cyclization, a selective 1,2-syn Mukaiyama aldol reaction, and a Noyori reduction.
- Dias, Luiz C.,Ferreira, Marco A. B.
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scheme or table
p. 4046 - 4062
(2012/06/29)
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- Total synthesis of the marine toxin phorboxazole A using palladium(ii)-mediated intramolecular alkoxycarbonylation for tetrahydropyran synthesis
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The potent antitumor agent phorboxazole A was synthesized from six subunits comprising C1-C2 (115), C3-C8 (98), C9-C19 (74), C20-C32 (52), C33-C41 (84) and C42-C46 (85). Tetrahydropyrans B and C containing cis-2,6-disubstitution were fabricated via palladium(ii)-mediated intramolecular alkoxycarbonylation which, in the case of tetrahydropyran C, was carried out with catalytic palladium(ii) and p-benzoquinone as the stoichiometric re-oxidant. Tetrahydropyran D was obtained by a stereoselective tin(iv)-catalyzed coupling of a C9 aldehyde with an allylsilane, and the C19-C20 connection was made using a completely stereoselective Wittig-Schlosser (E) olefination. Coupling of the oxazole C32 methyl substituent with the intact C33-C46 δ-lactone 3 was accompanied by elimination of the vinyl bromide to a terminal alkyne, but the C32-C33 linkage was implemented successfully with 83 and C33-C41 lactone 84. The C42-C46 segment of the side chain was then appended via Julia-Kocienski olefination. The macrolide portion of phorboxazole A was completed by means of an Ando-Still-Gennari intramolecular (Z)-selective olefination at C2-C3 which required placement of a (dimethoxyphosphinyl)acetate moiety at C24. Final deprotection led to phorboxazole A via a route in which the longest linear sequence is 37 steps and the overall yield is 0.36%.
- Kuntiyong, Punlop,Lee, Tae Hee,Kranemann, Christian L.,White, James D.
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supporting information
p. 7884 - 7899
(2013/07/05)
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- Synthesis and antioxidant properties of an unnatural plasmalogen analogue bearing a trans O-vinyl ether linkage
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To assess the antioxidant behavior of trans-1, we first synthesized trans-allyl ether 4 by opening an (S)-glycildol derivative with an (E)-alk-2en-ol, and then produced the unnatural E-enol ether 1 by a stereoselective iridium(I)-catalyzed olefin isomerization. Natural cis-1 was preferentially degraded by HOCI and was more protective than trans-1 against lipid peroxidation Induced by a free-radical Initiator, demonstrating that the geometry of the 1-alkenyloxy bond participates In the antioxidant defensive role of 1.
- Lankalapalli, Ravi S.,Eckelkamp, Joseph T.,Sircar, Debajit,Ford, David A.,Subbaiah, Papasani V.,Bittman, Robert
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supporting information; experimental part
p. 2784 - 2787
(2009/12/05)
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- Enantioselective total synthesis of brevetoxin A: Unified strategy for the B, E, G, and J subunits
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Brevetoxin A is a decacyclic ladder toxin that possesses 5-, 6-, 7-, 8-, and 9-membered oxacycles, as well as 22 tetrahedral stereocenters. Herein, we describe a unified approach to the B, E, G, and J rings based upon a ring-closing metathesis strategy from the corresponding dienes. The enolate technologies developed in our laboratory allowed access to the precursor acyclic dienes for the B, E, and G medium-ring ethers. The strategies developed for the syntheses of these four monocycles ultimately provided multigram quantities of each of the rings, supporting our efforts toward the completion of a convergent synthesis of brevetoxin A.
- Crimmins, Michael T.,Ellis, J. Michael,Emmitte, Kyle A.,Haile, Pamela A.,McDougall, Patrick J.,Parrish, Jonathan D.,Zuccarello, J. Lucas
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supporting information; experimental part
p. 9223 - 9234
(2010/04/25)
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- A transannular diels-alder strategy to the construction of the CDE ring system of nakiterpiosin
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The transannular Diels-Alder (TADA) reaction was applied to the synthesis of the CDE ring system of nakiterpiosin (1). TADA product 28 is a key intermediate toward the total synthesis of 1.
- Takamura, Hiroyoshi,Yamagami, Yuji,Ito, Tomonori,Ito, Masahiro,Arimoto, Hirokazu,Kadota, Isao,Uemurat, Daisuke
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experimental part
p. 351 - 364
(2009/09/06)
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- Total synthesis of (-)-histrionicotoxin 285A and (-)- perhydrohistrionicotoxin
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(Chemical Equation Presented) Starting from commercially available (S)-glycidol, and via a common intermediate, the total synthesis of (-)-histrionicotoxin 285A and (-)-perhydrohistrionicotoxin has been achieved. Key to this synthesis was the efficient co
- Macdonald, James M.,Horsley, Helen T.,Ryan, John H.,Saubern, Simon,Holmes, Andrew B.
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supporting information; experimental part
p. 4227 - 4229
(2009/06/06)
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- Synthesis of the C8-C20 and C21-C30 segments of pectenotoxin 2
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In this study, we synthesized the C8-C20 and C21-C30 segments of the diarrhetic shellfish toxin pectenotoxin 2. The C8-C20 segment was assembled from a phosphonate corresponding to the C8-C15 segment (prepared from l-malic acid in 19 steps) and an aldehyd
- Fujiwara, Kenshu,Aki, Yu-ichi,Yamamoto, Fuyuki,Kawamura, Mariko,Kobayashi, Masanori,Okano, Azusa,Awakura, Daisuke,Shiga, Shunsuke,Murai, Akio,Kawai, Hidetoshi,Suzuki, Takanori
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p. 4523 - 4527
(2008/02/03)
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- Studies toward the total synthesis of nakiterpiosin: construction of the CDE ring system by a transannular Diels-Alder strategy
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The transannular Diels-Alder (TADA) reaction was applied to the synthesis of the CDE ring system of nakiterpiosin (1). Tetracyclic compound 25 may be a key intermediate in the total synthesis of 1.
- Ito, Tomonori,Ito, Masahiro,Arimoto, Hirokazu,Takamura, Hiroyoshi,Uemura, Daisuke
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p. 5465 - 5469
(2008/02/10)
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- Synthesis of the C1-C52 fragment of amphidinol 3, featuring a β-alkoxy alkyllithium addition reaction
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(Chemical Equation Presented) An advanced intermediate for the synthesis of amphidinol 3 has been prepared. A cross-metathesis reaction was used to couple the C1-C12 and C13-C26 segments. An unusual β-alkoxy alkyllithium reagent was generated from this se
- Huckins, John R.,De Vicente, Javier,Rychnovsky, Scott D.
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p. 4757 - 4760
(2008/03/14)
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- Total synthesis of (R)-(+)-goniothalamin and (R)-(+)-goniothalamin oxide: first application of the sulfoxide-modified Julia olefination in total synthesis
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A short and efficient synthesis of (R)-(+)-goniothalamin 1 and (R)-(+)-goniothalamin oxide 2 is described. During this approach, the sulfoxide-modified Julia olefination was used as a key step to connect aldehyde 5 to sulfoxide 6. The desired styryl-containing adduct is obtained in good yield and with excellent E/Z selectivity.
- Pospí?il, Ji?í,Markó, István E.
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p. 5933 - 5937
(2007/10/03)
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- A highly enantioselective total synthesis of (+)-goniodiol
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A high-yielding enantioselective total synthesis of the bioactive styryllactone (+)-goniodiol has been realised, starting from readily available (S)-glycidol. A key step is an oxygen-to-carbon rearrangement of a silyl enol ether linked via an anomeric cen
- Tate, Edward W.,Dixon, Darren J.,Ley, Steven V.
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p. 1698 - 1706
(2008/02/11)
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- 4,5-Didehydro-7-silyloxymethyl-2-oxepanone and formal total syntheses of Hagen's gland lactones and trans-kumausynes
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A concise and enantiospecific route to the 2,6-dioxabicyclo[3.3.0]octan-3-one ring system from commercially available (R)-(+)- and (S)-(-)-glycidols is described. The key features involve ring closing metathesis to construct the 7-substituted-4,5-dehydro-
- Agrawal, Divya,Sriramurthy, Vardhineedi,Yadav, Veejendra K.
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p. 7615 - 7618
(2007/10/03)
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- Convergent, stereoselective synthesis of the GHIJ fragment of brevetoxin A
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(Chemical Equation Presented) A stereoselective synthesis of the GHIJ fragment of brevetoxin A utilizing a convergent assembly strategy is described. Glycolate alkylation, ring-closing metathesis, and Hosomi-Sakurai reactions were central operations in the construction of the G ring and J ring subunits, which were united through a Horner-Wadsworth-Emmons coupling. Subsequent dehydrative cyclization produced an endocyclic enol ether that was further elaborated to the tetracyclic GHIJ fragment of brevetoxin A.
- Crimmins, Michael T.,Zuccarello, J. Lucas,Cleary, Pamela A.,Parrish, Jonathan D.
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p. 159 - 162
(2007/10/03)
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- LAULIMALIDE ANALOGS AND USES THEREOF
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The present invention provides compounds having formula 1: (I) and pharmaceutically acceptable derivatives thereof, wherein R1-R10, q, t, X0, X1, A, B, D, E, G, J, K, L, M and Z are as described generally and in classes and subclasses herein, and additionally provides pharmaceutical compositions thereof, and methods for the use thereof for the treatment of disorders associated with cellular hyperproliferation.
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Page/Page column 117-118
(2010/02/11)
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- Organocatalytic kinetic resolution of racemic primary alcohols using a chiral 1,2-diamine derived from (S)-proline
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A highly efficient and good enantioselective organocatalytic asymmetric acylation of racemic primary alcohols with acyl chlorides has been achieved catalyzed by a chiral 1,2-diamine derived from (S)-proline.
- Terakado, Dai,Koutaka, Hitomi,Oriyama, Takeshi
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p. 1157 - 1165
(2007/10/03)
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- Anomeric oxygen to carbon rearrangements of alkynyl tributylstannane derivatives of furanyl (γ)- and pyranyl (δ)-lactols
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Tetrahydropyran and tetrahydrofuran containing natural products, drugs and agrochemicals often possess carbon-carbon bonds adjacent to the heteroatom. Consequently, new methods for the construction of anomeric carbon-carbon bonds are of considerable importance. We have devised a new strategy to access these systems that requires the treatment of O-glycoside alkynyl tributylstannane derivatives of furanyl and pyranyl lactols with Lewis acid to effect oxygen to carbon rearrangements. This leads to the formation of the corresponding carbon linked alkynol products that can be further manipulated to produce key structural motifs and building blocks for the assembly of complex molecules.
- Buffet, Marianne F.,Dixon, Darren J.,Ley, Steven V.,Reynolds, Dominic J.,Storer, R. Ian
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p. 1145 - 1154
(2007/10/03)
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- First total synthesis and determination of the absolute configuration of strictifolione, a new 6-(ω-phenylalkenyl)-5,6-dihydro-α-pyrone, isolated from Cryptocarya strictifolia
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Starting from (S)-malic acid and (S)-glycidol, the first total synthesis of strictifolione, a new 6-(ω-phenylalkenyl)-5,6-dihydro-α-pyrone isolated from Cryptocarya strictifolia, was accomplished, which confirmed its structure including the absolute confi
- Juliawaty, Lia Dewi,Watanabe, Yoshimi,Kitajima, Mariko,Achmad, Sjamsul Arifin,Takayama, Hiromitsu,Aimi, Norio
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p. 8657 - 8660
(2007/10/03)
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- The total synthesis of the annonaceous acetogenin, muricatetrocin C
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The total synthesis of the potential antitumour agent muricatetrocin C has provided an ideal stage for the exploitation and development of new chemistry. A convergent synthetic strategy has been realised incorporating three distinct pieces of methodology, these include a highly diastereoselective hetero-Diels -Alder reaction to construct the butenolide terminus, an oxygen to carbon rearrangement to install the trans-2,5-disubstituted tetrahydrofuran ring and a spatial desymmetrisation process to afford the anti-diol unit.
- Dixon, Darren J.,Ley, Steven V.,Reynolds, Dominic J.
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p. 1621 - 1636
(2007/10/03)
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- A short and efficient stereoselective synthesis of the potent 5-lipoxygenase inhibitor, CMI-977
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A short and efficient synthesis of the potent 5-lipoxygenase inhibitor CMI-977 has been accomplished, utilising an oxygen to carbon rearrangement of an anomerically linked alkynyl stannane tetrahydrofuranyl ether derivative as the key step.
- Dixon,Ley,Reynolds,Chorghade
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p. 1043 - 1053
(2007/10/03)
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- Highly enantiopure (tert-butyldiphenylsilyloxymethyl)oxiranes from barium carbonate
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The synthesis of (2R)-(tert-butyldiphenylsilyloxymethyl)oxirane and the (2S)-enantiomer from barium carbonate was developed. Methyl glycolate or the hydroxamate analog was prepared and in turn reacted with (S)-(-)-methyl p- tolylsulfoxide or the (R)-enantiomer to make β-keto sulfoxides. From the sulfoxides, we made the diastereoisomeric alcohols in a highly selective sulfoxide group directed hydride reduction, and a Pummerer rearrangement reaction followed by deprotection yielded the enantiomeric diols. (2R)- (tert-Butyldiphenylsilyloxymethyl)oxirane and its (2S)-enantiomer were derived from these diols in an overall yield of 56 % from barium carbonate. This method was developed to provide a convenient access to isotope-labeled analogs of these compounds.
- Ekhato, I. Victor,Palazzolo, Mark
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p. 3727 - 3741
(2007/10/03)
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- Total synthesis of callystatin A, a potent cytotoxic polyketide from the marine sponge, Callyspongia truncata
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A first total synthesis of callystatin A (1), a potent cytotoxic polyketide from the marine sponge Callyspongia truncata, has been achieved by use of an E-selective Wittig olefination and asymmetric Evans aldol condensation as the key reactions. Thus, the
- Murakami, Nobutoshi,Wang, Weiqi,Aoki, Masashi,Tsutsui, Yasuhiro,Sugimoto, Masanori,Kobayashi, Motomasa
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p. 2349 - 2352
(2007/10/03)
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- A total synthesis of (+)-Goniodiol using an anomeric oxygen-to-carbon rearrangement
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A new route to (+)-Goniodiol 1, a potent and selective cytotoxin, is described, using a diastereoselective oxygen-to-carbon rearrangement of an anomerically linked silyl enol ether as the key step.
- Dixon, Darren J.,Ley, Steven V.,Tate, Edward W.
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p. 3125 - 3126
(2007/10/03)
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- The olefin metathesis approach to epothilone A and its analogues
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The olefin metathesis approach to epothilone A (1) and several analogues (39-41, 42-44, 51-57, 58-60, 64-65, and 67-69) is described. Key building blocks 6-8 were constructed in optically active form and were coupled and elaborated to olefin metathesis pr
- Nicolaou,He,Vourloumis,Vallberg,Roschangar,Sarabia,Ninkovic,Yang,Trujillo
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p. 7960 - 7973
(2007/10/03)
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- Durch Olefinmetathese zum Epothilongeruest
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Keywords: Cyclisierungen; Epothilone; Naturstoffe; Olefinmetathese; Synthesemethoden
- Nicolaou, K. C.,He, Yun,Vourloumis, Dionisios,Vallberg, Hans,Yang, Zhen
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p. 2554 - 2556
(2007/10/03)
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- A General Synthetic Route for Preparing Ether Phospholipids Suitable for Immobilization: A Phosphotriester Approach
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A synthetic route was developed to prepare ether phospholipid (PL) ligands suitable for immobilization.PL ligand design included an ω-carboxyl functional group to assure proper molecular orientation during immobilization; i.e., the polar lipid head group protrudes from the surface.However, during immobilization, PL ligands required protecting groups to eliminate the possibility of the PL binding upside down.Four synthetic PL ligands were prepared that contain both ω-carboxyl groups for immobilization and protecting groups in the polar head group; these carboxyl-PLligands are analogs of phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylglycerol (PG), and phosphatidic acid (PA).The critical synthetic step during PL synthesis is the phosphorylation step which usually has the lowest yield of all other steps.This is the first report demonstrating that o-chlorophenyl dichloro phosphate (CPDCP) can be used as a mild phosphorylation reagent for the preparation of PL analogs.Phosphorylation with CPDCP is routinely 50-90percent efficient depending on the analog, but more important is that the protecting groups associated with PE, PS, PG, and PA are stable during this critical synthetic step.After immobilization of the carboxyl-PL ligands, acidic or basic solution conditions are needed for deprotection and generation of free PE, PG, PS, and PA polar lipid head groups which protrude from the surface.This work demonstrates that CPDCP is an excellent synthetic reagent for all ether PL analogs either with or without ω-carboxyl functional groups.
- Qiu, Xiaoxing,Ong, Shaowei,Bernal, Candido,Rhee, Dongmi,Pidgeon, Charles
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p. 537 - 543
(2007/10/02)
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