- Formal Total Synthesis of Hybocarpone Enabled by Visible-Light-Promoted Benzannulation
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The formal total synthesis of hybocarpone was achieved in eight steps from commercially available 1,2,4-trimethoxybenzene. Key transformations include a visible-light-promoted benzannulation to construct the key α-naphthol intermediate and a modified CAN-mediated dimerization/hydration cascade sequence to generate the vicinal all-carbon quaternary centers in a stereocontrolled manner. The total synthesis of boryquinone was also achieved in seven steps.
- Chen, Wei,Guo, Renyu,Yang, Zhen,Gong, Jianxian
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- Catalytic Asymmetric Crotylation of Aldehydes: Application in Total Synthesis of (-)-Elisabethadione
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A new, highly efficient Lewis base catalyst for a practical enantio- and diastereoselective crotylation of unsaturated aldehydes with E- and Z-crotyltrichlorosilanes has been developed. The method was employed as a key step in a novel asymmetric synthesis of bioactive serrulatane diterpene (-)-elisabethadione. Other strategic reactions for setting up the stereogenic centers included anionic oxy-Cope rearrangement and cationic cyclization. The synthetic route relies on simple, high yielding reactions and avoids use of protecting groups or chiral auxiliaries.
- O'Hora, Paul S.,Incerti-Pradillos, Celia A.,Kabeshov, Mikhail A.,Shipilovskikh, Sergei A.,Rubtsov, Aleksandr E.,Elsegood, Mark R. J.,Malkov, Andrei V.
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supporting information
p. 4551 - 4555
(2015/03/18)
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- Formal synthesis of 7-methoxymitosene and synthesis of its analog via a key PtCl2-catalyzed cycloisomerization
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A formal synthesis of 7-methoxymitosene is achieved via a key platinum-catalyzed cycloisomerization. The precursor for the Pt catalysis, a fully functionalized benzene intermediate, was prepared via a regioselective electrophilic bromination followed by a
- Liu, Lianzhu,Wang, Yanzhao,Zhang, Liming
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scheme or table
p. 3736 - 3739
(2012/09/21)
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- Synthesis of 1,2,4-trimethoxybenzene and its selective functionalization at C-3 by directed metalation
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A new and efficient strategy was developed for the preparation of 1,2,4-trimethoxybenzene (3, a powerful attractant of Euglossini bees) and its C-3 derivatives (7a-j), from vanillin (2) in 56% overall yield.
- Alves, Ana P. L.,Junior, Jose Augusto B. C.,Slana, Glaucia B. A.,Cardoso, Jari N.,Wang, Qiang,Lopes, Rosangela S. C.,Lopes, Claudio C.
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experimental part
p. 3693 - 3709
(2009/12/06)
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- Enantioselective synthesis of the sporolide quinone acid fragment
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The sporolide quinone acid is a key fragment in the biosynthesis of the complex heptacyclic marine metabolite sporolide. We report a concise enantioselective route to this fragment, which is obtained in seven steps with 65% overall yield from trimethoxybe
- Wach, Jean-Yves,Gademann, Karl
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scheme or table
p. 2849 - 2851
(2010/03/03)
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- Gold(I)-catalyzed intramolecular [4+2] cycloadditions of arylalkynes or 1,3-enynes with alkenes: Scope and mechanism
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The cyclizations of enynes substituted at the alkyne gives products of formal [4+2] cyclization with Au(I) catalysts. 1,8-Dien-3-ynes cyclize by a 5-exo-dig pathway to form hydrindanes. 1,6-Enynes with an aryl ring at the alkyne give 2,3,9,9a-tetrahydro-1
- Nieto-Oberhuber, Cristina,Perez-Galan, Patricia,Herrero-Gomez, Elena,Lauterbach, Thorsten,Rodriguez, Cristina,Lopez, Salome,Bour, Christophe,Rosellon, Antonio,Cardenas, Diego J.,Echavarren, Antonio M.
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p. 269 - 279
(2008/09/20)
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- Rust disease control by Aphanocladium album and/or Beauveria brongniartii
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There is disclosed a method and composition for controlling rust disease in plants. Metabolites produced by Aphanocladium album mycoparasites are recovered and applied in an effective amount to plants at risk for acquiring rust disease More specifically,
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Page/Page column 19
(2010/11/27)
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- Combined C-H activation/cope rearrangement as a strategic reaction in organic synthesis: Total synthesis of (-)-colombiasin A and (-)-elisapterosin B
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The total synthesis of (-)-colombiasin A (2) and (-)-elisapterosin B (3) has been achieved. The key step is a C-H functionalization process, the combined C-H activation/Cope rearrangement, between methyl (E)-2-diazo-3-pentenoate and 1-methyl-1,2-dihydrona
- Davies, Huw M. L.,Dai, Xing,Long, Matthew S.
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p. 2485 - 2490
(2007/10/03)
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- Synthesis of a Diels-Alder precursor for the Elisabethin A skeleton
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A synthesis of a precursor 2 for the Elisabethin A skeleton is reported. Containing a masked quinone and a (E,Z)-diene sub-unit, it has the required elements for the envisaged intramolecular Diels-Alder reaction to form the tricyclic system of Elisabethin A. Starting from methylresorcinol, the sequence involves the preparation of an arylacetic acid, which was α-alkylated by a chiral building block. Subsequent HWE reaction and cis-selective Wittig olefination furnished the diene with the desired geometry.
- Heckrodt, Thilo J.,Mulzer, Johann
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p. 1857 - 1866
(2007/10/03)
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- ortho-Directed metallation in the regiocontrolled synthesis of enantiopure 2- and/or 3-substituted (S)S (p-tolylsulfinyl)-1,4-benzoquinones
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Enantiomerically pure (S)S-(p-tolylsulfinyl)-1,4-benzoquinones with alkyl and methoxy substituents at C-2 and/or C-3 are synthesized by CAN oxidation of adequately substituted (S)S-(p-tolylsulfinyl)-1,4-dimethoxyaromatic precursors 2 or 3. These compounds were obtained by ortho-directed metallation or bromo-metal exchange from the corresponding p-methoxyanisoles in a highly regiocontrolled manner.
- Carreno, M. Carmen,Garcia Ruano, Jose L.,Toledo, Miguel A.,Urbano, Antonio
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p. 913 - 921
(2007/10/03)
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- Biaryl formation using the Suzuki protocol: Considerations of base, halide, and protecting group
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The generation of aryl anions prior to quenching with a trialkyl berate has been shown to be sensitive to the composition of the aryl substrate. Aryl iodides containing remote benzyl ether substituents undergo trans-metallation with sec-BuLi to cleanly give the desired aryl anions whereas the corresponding bromides afford appreciable quantities of dianionic intermediates. The aryl boronic acids derived from alkylation of these anions subsequently undergo a palladium mediated coupling with aryl halides to provide good yields of the desired biaryls. Copyright (C) 1996 Elsevier Science Ltd.
- Benbow, John W.,Martinez, Bonnie L.
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p. 8829 - 8832
(2007/10/03)
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- Lewis Acid Mediated Claisen-Type Rearrangement of Aryl Dienyl Ethers
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Rearrangement of aryl pentadienyl ethers in the presence of BF3*OEt2 affords pentadienyl phenols in good yields without formation of the corresponding rearranged products.The mechanism of this rearrangement was studied by deuterium labeling and cross-coupling reactions.The scope and limitations of the rearrangement are discussed.
- Maruyama, Kazuhiro,Nagai, Naoshi,Naruta, Yoshinori
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p. 5083 - 5092
(2007/10/02)
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- Amine Addition to Unsymmetrical Benzoquinones
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New routes to 2-methoxy-3-methyl-1,4-benzoquinone and 4-methoxy-3-methyl-1,2-benzoquinone have been developed.Both quinones undergo highly regioselective oxidative amination with pyrrolidine and copper acetate, yielding aminoquinones related to the mitomy
- Luly, Jay R.,Rapoport, Henry
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p. 2745 - 2752
(2007/10/02)
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