- Formal synthesis of borrelidin: A highly enantio- and diastereoselective access to the Morken's C2-C12 intermediate
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In contrast to methyl and isobutyl phenyl sulfone, condensing under basic conditions higher alkyl sulfones and trans-2,3-epoxy-butanol 13c (or its O-benzyl and O-silyl derivatives) proved unfeasible, a difficulty that was overcome by using mono ethers of trans-2,3-epoxy-butane-1,4-diol 35c as the electrophilic reagents. Thus, adding excess BuLi to a mixture of the benzyl ether 35b and sulfone ent-12a, a stereodiad sulfone prepared in pure state from the R-Roche ester, via the O-trityloxy-sulfone ent-12c (X-ray), gave, after elimination by column chromatography of the side-formed regioisomer, a diolsulfone that was next converted to sulfone 20 by means of conventional functional-group modifications. Reacting like-wise this sulfone with the parent O-PMB derivative 35a, and then proceeding to the same purification process and function adjustment, delivered the title fragment in virtually pure state.
- Gembus, Vincent,Karmazin, Lydia,Uguen, Daniel,Zoller, Thomas
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supporting information
p. 359 - 380
(2019/02/25)
-
- Screening of a virtual mirror-image library of natural products
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We established a facile access to an unexplored mirror-image library of chiral natural product derivatives using d-protein technology. In this process, two chemical syntheses of mirror-image substances including a target protein and hit compound(s) allow the lead discovery from a virtual mirror-image library without the synthesis of numerous mirror-image compounds.
- Noguchi, Taro,Oishi, Shinya,Honda, Kaori,Kondoh, Yasumitsu,Saito, Tamio,Ohno, Hiroaki,Osada, Hiroyuki,Fujii, Nobutaka
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supporting information
p. 7653 - 7656
(2016/07/06)
-
- Gold(I)-catalyzed synthesis of unsymmetrical ethers using alcohols as alkylating reagents
-
A microwave-irradiated alcohol-protecting strategy based on gold catalysis utilizing benzyl alcohol, tert-butyl alcohol and triphenylmethanol as alkylating reagents has been developed. This protecting strategy has wide functional group tolerance with satisfactory yields for the majority of the selected alcohols. The mechanism of this transformation was probed with oxygen-18 isotope labelled alcohols assisted by GC-MS techniques and chemical kinetic experiments. This strategy provides an efficient, straightforward and alternative approach to the preparation of benzyl, tert-butyl and trityl ethers in organic synthesis.
- Liu, Yongxiang,Wang, Xiaoyu,Wang, Yanshi,Du, Chuan,Shi, Hui,Jin, Shengfei,Jiang, Chongguo,Xiao, Jianyong,Cheng, Maosheng
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p. 1029 - 1036
(2015/03/30)
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- Biomimetic total synthesis of cruentaren A via aromatization of diketodioxinones
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The total synthesis of cruentaren A, a biologically active resorcylate natural product, is reported. The aromatic unit was constructed via late-stage cyclization and aromatization from a diketodioxinone intermediate and macrocyclization using Fuerstner ring-closing alkyne metathesis.
- Fouche, Marianne,Rooney, Lisa,Barrett, Anthony G. M.
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experimental part
p. 3060 - 3070
(2012/05/20)
-
- SUBSTITUTED FUROPYRIMIDINES AND USE THEREOF
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The present application relates to novel substituted furopyrimidine derivatives, to processes for their preparation, to their use for the treatment and/or prophylaxis of diseases and to their use for preparing medicaments for the treatment and/or prophylaxis of diseases, especially for the treatment and/or prophylaxis of cardiovascular diseases.
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Page/Page column 29
(2011/07/29)
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- Novel, Acyclically Substituted Furopyrimidine Derivatives and Use Thereof
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The present application relates to novel, acyclically substituted furopyrimidine derivatives, methods for their production, their use for the treatment and/or prophylaxis of diseases and their use for the production of medicinal products for the treatment and/or prophylaxis of diseases, in particular for the treatment and/or prophylaxis of cardiovascular diseases.
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Page/Page column 28
(2009/12/28)
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- Synthesis of the macrocyclic core of (-)-pladienolide B
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(Chemical Equation Presented) An efficient synthesis of the macrocyclic core of (-)-pladienolide B is disclosed. The concise route relies on a chiral auxiliary-mediated asymmetric aldol addition and an osmium-catalyzed asymmetric dihydroxylation to install the three oxygenated stereocenters of the macrocycle. This purely reagent-controlled and flexible strategy sets the stage for future analogue syntheses and structure-activity relationship plotting of the appealing anticancer lead structure pladienolide B.
- Skaanderup, Philip R.,Jensen, Thomas
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supporting information; experimental part
p. 2821 - 2824
(2009/05/27)
-
- Vanadium-catalyzed asymmetric epoxidation of homoallylic alcohols
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New chiral bishydroxamic acids were synthesized and tested as chiral ligands in the vanadium-catalyzed asymmetric epoxidation of homoallylic alcohols to provide good yields and high enantioselectivities. Copyright
- Zhang, Wei,Yamamoto, Hisashi
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p. 286 - 287
(2008/04/18)
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- Synthesis of the C-1-C-28 ABCD Unit of Spongistatin 1
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(Equation Presented) The synthesis of the C-1-C-28 ABCD fragment of spongistatin is described. Anti-selective boron-mediated aldol coupling of a CD spiroketal ketone fragment to an AB spiroketal aldehyde unit forms the desired C1-C28 advanced intermediate
- Gaunt, Matthew J.,Jessiman, Alan S.,Orsini, Paolo,Tanner, Huw R.,Hook, David F.,Ley, Steven V.
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p. 4819 - 4822
(2007/10/03)
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- Formal total synthesis of altohyrtin C (spongistatin 2). Part 1: Aldol approach to unite AB and CD spiroacetals
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The Mukaiyama aldol coupling of the second-generation C1-C14 (AB) fragment of altohyrtins (spongistatins) with the model α-methyl-β -alkoxyaldehydes revealed that the stereochemistry at the newly formed carbon centers was controlled by the β-alkoxy chiral center of the model aldehydes. The union of the AB fragment with the C15-C28 (CD) fragment under the same conditions gave the fully elaborated C1-C28 (ABCD) subunit in good yield.
- Terauchi, Takeshi,Terauchi, Taro,Sato, Ippei,Shoji, Wataru,Tsukada, Tomoharu,Tsunoda, Takashi,Kanoh, Naoki,Nakata, Masaya
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p. 7741 - 7745
(2007/10/03)
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- Stereochemical elucidation of the 1,4 polyketide amphidinoketide I.
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The relative and absolute stereochemistry of amphidinoketide I has been determined by the total synthesis of all the diastereoisomers. Molecular modelling suggests that the natural product is not the thermodynamically preferred diastereoisomer.
- Walsh, Louise M,Goodman, Jonathan M
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p. 2616 - 2617
(2007/10/03)
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- Azole antifungal agents, processes for the preparation thereof, and intermediates
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A compound represented by the general formula: wherein R1 and R2 denote a halogen atom or hydrogen atoms; R3 means a hydrogen atoms or lower alkyl group; r and m stand for 0 or 1; A is N or CH; W denotes an aromatic ring or a condensed ring thereof; X means another aromatic rings, an alkanediyl group, an alkenediyl group, or an alkynediyl group; Y stand for -S-, etc.; Z denotes a hydrogen atom, etc., or a salt thereof, and intermediates thereof or a salt thereof as well as processes for the preparation thereof, and pharmacetical composition suitable for use as an antifungal agent.
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Page 118-120
(2010/01/31)
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- Room-temperature metallation of 2-substituted 1,3-dithiane derivatives and subsequent coupling with 2,3-disubstituted oxiranes
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2-Substituted 1,3-dithiane derivatives, (S)-1(t-butyldiphenylsiloxy)-2- (1,3-dithian-2-yl)propane (9), (S)-1-(t-butyldimethylsiloxy)-2-(1,3-dithian- 2-yl)propane, 1-(t-butyldiphenylsiloxy)-2-(1,3-dithian-2-yl)-2-methylpropane, and 1,2-bis-(t-butyldiphenylsiloxy)-3-(1,3-dithian-2-yl)propane, were subjected to lithiation in THF with n-BuLi at room temperature (r.t.); the resulting anions reacted with 2,3-disubstituted oxirane, trans-2-methyl-3- (triphenylmethoxymethyl)oxirane(22), at r.t., giving the coupling products in satisfactory yield. On the other hand, the lithium salt formed in ether from (S)2-(1,3-dithian-2-yl)-1-(4-methoxybenzyloxy)propane with n-BuLi at r.t. reacted with 22 at r.t. in the presence of hexamethylphosphoric triamide to afford the coupling product in moderate yield. In addition, a mixed organometallic reagent, n-BuLi/Bu2Mg, was found to be an effective metallation reagent for 9 and the resulting anion reacted with 22 to afford the coupling product in good yield.
- Ide, Mitsuaki,Nakata, Masaya
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p. 2491 - 2499
(2007/10/03)
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- Benzyl trityl ether and DDQ as new tritylating reagents
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We describe herein a new tritylation procedure of alcohols using benzyl trityl ether and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. The reaction involves oxidative abstraction of one of the benzylic protons of benzyl trityl ether, followed by transformation of the generated benzyl trityl ether cation into a complex of benzaldehyde and trityl cation. The present procedure proceeds under mild neutral conditions to afford trityl ethers in generally good yields for primary alcohols, and in acceptable yields for several secondary alcohols.
- Oikawa, Masato,Yoshizaki, Hiroaki,Kusumoto, Shoichi
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p. 757 - 760
(2007/10/03)
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- A novel route for chiral synthesis of the triazole antifungal ER-30346
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A novel synthetic route to (2S,3S)-2-(2,4-difluorophenyl)-3-hydroxy-2- methyl-4-(1-(1,2,4-triazolyl))butyronitrile (2), an intermediate for the orally active triazole antifungal agent ER-30346, was developed from methyl S-(+)-3-hydroxy-2-methylpropionate,
- Kaku, Yumiko,Tsuruoka, Akihiko,Kakinuma, Hiroyuki,Tsukada, Itaru,Yanagisawa, Manabu,Naito, Toshihiko
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p. 1125 - 1129
(2007/10/03)
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- Generation of 2-substituted-2-metallo-1,3-dithianes and their coupling with 1,2-disubstituted epoxides at room temperature
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2-Substituted-1,3-dithianes were subjected to lithiation by n-BuLi at room temperature and the resulting anions reacted with 1,2-disubstituted epoxides at room temperature, giving the coupling products in satisfactory yield. In addition, a mixed organomet
- Ide, Mitsuaki,Yasuda, Minora,Nakata, Masaya
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p. 936 - 938
(2007/10/03)
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- Heteroatom-Assisted Substitution of Acyclic Secondary Tosylates with Lithium Dialkylcuprates: An Expedient Route to Stereochemically Defined Deoxypropionate and Related Biosynthetic Subunits
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Secondary tosylates of a number of acyclic molecules can be easily displaced with diorganocuprates with complete inversion of configuration.The displacement reaction is greatly facilitated when a hetero atom (S or O) is proximal to the nucleofugal group a
- Hanessian, S.,Thavonekham, B.,DeHoff, B.
-
p. 5831 - 5833
(2007/10/02)
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