137688-20-1Relevant articles and documents
Enantioselectivities of yeast epoxide hydrolases for 1,2-epoxides
Botes, Adriana L.,Weijers, Carel A. G. M.,Botes, Piet J.,Van Dyk, Martie S.
, p. 3327 - 3336 (1999)
Kinetic resolution of homologous series of unbranched 1,2-epoxyalkanes (C-4 to C-12), 1,2-epoxyalkenes (C-4, C-6 and C-8), a 2,2-dialkylsubstituted epoxide (2-methyl-1,2-epoxyheptane) and a benzyloxy-substituted epoxide (benzyl glycidyl ether) was investigated using resting cells of 10 different yeast strains. Biocatalysts with excellent enantioselectivity (E>100) and high initial reaction rates (>300 nmol/min/mg dry weight) were found for the 2-monosubstituted aliphatic epoxides C-6 to C-8. Yeast strains belonging to the genera Rhodotorula, Rhodosporidium and Trichosporon all preferentially hydrolyzed (R)-1,2-epoxides with retention of configuration. The epoxide hydrolases of all the yeast strains are membrane-associated.
Identification, synthesis and mass spectrometry of a macrolide from the African reed frog Hyperolius cinnamomeoventris
Menke, Markus,Peram, Pardha Saradhi,Starnberger, Iris,H?dl, Walter,Jongsma, Gregory F. M.,Blackburn, David C.,R?del, Mark-Oliver,Vences, Miguel,Schulz, Stefan
supporting information, p. 2731 - 2738 (2017/01/09)
The contents of the gular glands of the male African reed frog Hyperolius cinnamomeoventris consist of a mixture of aliphatic macrolides and sesquiterpenes. While the known macrolide gephyromantolide A was readily identified, the structure of another major component was suggested to be a tetradecen-13-olide. The synthesis of the two candidate compounds (Z)-5- and (Z)-9-tetradecen-13-olide revealed the former to be the naturally occurring compound. The synthesis used ring-closing metathesis as key step. While the Hoveyda-Grubbs catalyst furnished a broad range of isomeric products, the (Z)-selective Grubbs catalyst lead to pure (Z)-products. Analysis by chiral GC revealed the natural frog compound to be (5Z,13S)-5-tetradecen-13-olide (1). This compound is also present in the secretion of other hyperoliid frogs as well as in femoral glands of male mantellid frogs such as Spinomantis aglavei. The mass spectra of the synthesized macrolides as well as their rearranged isomers obtained during ring-closing metathesis showed that it is possible to assign the location of the double bond in an unsaturated macrolide on the basis of its EI mass spectrum. The occurrence of characteristic ions can be explained by the fragmentation pathway proposed in the article. In contrast, the localization of a double bond in many aliphatic open-chain compounds like alkenes, alcohols or acetates, important structural classes of pheromones, is usually not possible from an EI mass spectrum. In the article, we present the synthesis and for the first time elucidate the structure of macrolides from the frog family Hyperoliidae.
Concise total syntheses of amphidinolides C and F
Valot, Galle,Mailhol, Damien,Regens, Christopher S.,O'Malley, Daniel P.,Godineau, Edouard,Takikawa, Hiroshi,Philipps, Petra,Fürstner, Alois
supporting information, p. 2398 - 2408 (2015/02/05)
The marine natural products amphidinolide C (1) and F (4) differ in their side chains but share a common macrolide core with a signature 1,4-diketone substructure. This particular motif inspired a synthesis plan predicating a late-stage formation of this non-consonant ("umpoled") pattern by a platinum-catalyzed transannular hydroalkoxylation of a cycloalkyne precursor. This key intermediate was assembled from three building blocks (29, 41 and 47 (or 65)) by Yamaguchi esterification, Stille cross-coupling and a macrocyclization by ring-closing alkyne metathesis (RCAM). This approach illustrates the exquisite alkynophilicity of the catalysts chosen for the RCAM and alkyne hydroalkoxylation steps, which activate triple bonds with remarkable ease but left up to five other p-systems in the respective substrates intact. Interestingly, the inverse chemoselectivity pattern was exploited for the preparation of the tetrahydrofuran building blocks 47 and 65 carrying the different side chains of the two target macrolides. These fragments derive from a common aldehyde precursor 46 formed by an exquisitely alkene-selective cobalt-catalyzed oxidative cyclization of the diunsaturated alcohol 44, which left an adjacent acetylene group untouched. The northern sector 29 was prepared by a two-directional Marshall propargylation strategy, whereas the highly adorned acid subunit 41 derives from d-glutamic acid by an intramolecular oxa-Michael addition and a proline-mediated hydroxyacetone aldol reaction as the key steps; the necessary Me3Sn-group on the terminus of 41 for use in the Stille coupling was installed via enol triflate 39, which was obtained by selective deprotonation/triflation of the ketone site of the precursor 38 without competing enolization of the ester also present in this particular substrate.
Process development of halaven: Synthesis of the C14-C35 fragment via iterative nozaki-hiyama-kishi reaction-williamson ether cyclization
Austad, Brian C.,Benayoud, Farid,Calkins, Trevor L.,Campagna, Silvio,Chase, Charles E.,Choi, Hyeong-Wook,Christ, William,Costanzo, Robert,Cutter, James,Endo, Atsushi,Fang, Francis G.,Hu, Yongbo,Lewis, Bryan M.,Lewis, Michael D.,McKenna, Shawn,Noland, Thomas A.,Orr, John D.,Pesant, Marc,Schnaderbeck, Matthew J.,Wilkie, Gordon D.,Abe, Taichi,Asai, Naoki,Asai, Yumi,Kayano, Akio,Kimoto, Yuichi,Komatsu, Yuki,Kubota, Manabu,Kuroda, Hirofumi,Mizuno, Masanori,Nakamura, Taiju,Omae, Takao,Ozeki, Naoki,Suzuki, Taeko,Takigawa, Teiji,Watanabe, Tomohiro,Yoshizawa, Kazuhiro
, p. 327 - 332 (2013/04/10)
Multikilogram manufacturing process of the Halaven C14-C35 fragment is described. The synthesis features convergent assembly of subunits by iterative asymmetric Ni/Cr-mediated coupling executed in fixed equipment. Georg Thieme Verlag Stuttgart - New York.
Total synthesis of amphidinolide f
Valot, Ga?lle,Regens, Christopher S.,O'Malley, Daniel P.,Godineau, Edouard,Takikawa, Hiroshi,Fürstner, Alois
supporting information, p. 9534 - 9538 (2013/09/23)
Orchestrated yet nonconsonant: The challenge posed by the "umpoled" 1,4-dioxygenation pattern characteristic for the polyketide frame of amphidinolide F was mastered by a late-stage ring-closing alkyne metathesis followed by a directed transannular hydration under the aegis of a carbophilic π-acid catalyst. This concordant strategy enabled a concise total synthesis of this enticing marine natural product. Copyright
Minimal fluorous tagging strategy that enables the synthesis of the complete stereoisomer library of SCH725674 macrolactones
Moretti, Jared D.,Wang, Xiao,Curran, Dennis P.
supporting information; experimental part, p. 7963 - 7970 (2012/06/30)
Four mixtures of four fluorous-tagged quasiisomers have been synthesized, demixed, and detagged to make all 16 stereoisomers of the macrocyclic lactone natural product Sch725674. A new bare-minimum tagging pattern needs only two tags-one fluorous and one nonfluorous-to encode four isomers. The structure of Sch725674 is assigned as (5R,6S,8R,14R,E)-5,6,8-trihydroxy-14- pentyloxacyclotetradec-3-en-2-one. Various comparisons of spectra of 32 lactones (16 with tags, 16 without) and 16 ester precursors (8 with tags, 8 without) provide insights into when and why related compounds have the same or different spectra.
ISOSELECTIVE POLYMERIZATION OF EPOXIDES
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Page/Page column 69; 75-76, (2009/04/25)
The present invention provides novel bimetallic complexes and methods of using the same in the isoselective polymerization of epoxides. The invention also provides methods of kinetic resolution of epoxides. The invention further provides polyethers with high enantiomeric excess that are useful in applications ranging from consumer goods to materials.
NEW CHIRAL SALEN CATALYSTS AND METHODS FOR THE PREPARATION OF CHIRAL COMPOUNDS FROM RACEMIC EPOXIDES BY USING THEM
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Page/Page column 39, (2009/01/24)
The present invention relates to new chiral salen catalysts and the preparation method of chiral compounds from racemic epoxides using the same. More specifically, it relates to new chiral salen catalysts that have high catalytic activity due to new molecular structures and have no or little racemization of the generated target chiral compounds even after the reaction is completed and can be also reused without catalyst regeneration treatment, and its economical preparation method to mass manufacture chiral compounds of high optical purity, which can be used as raw materials for chiral food additives, chiral drugs, or chiral crop protection agents, etc., using the new chiral salen catalysts.
Intramolecular cyclopropanation of unsaturated terminal epoxides and chlorohydrins
Hodgson, David M.,Ying, Kit Chung,Nuzzo, Irene,Freixas, Gloria,Kulikiewicz, Krystyna K.,Cleator, Ed,Paris, Jean-Marc
, p. 4456 - 4462 (2008/02/02)
Lithium 2,2,6,6-tetramethylpiperidide (LTMP)-induced intramolecular cyclopropanation of unsaturated terminal epoxides provides an efficient and completely stereoselective entry to bicyclo[3.1.0]hexan-2-ols and bicyclo[4.1.0]heptan-2-ols. Further elaboration of C-5 and C-6 stannyl-substituted bicyclo[3.1.0]-hexan-2-ols via Sn-Li exchange/electrophile trapping or Stille coupling generates a range of substituted bicyclic cyclopropanes. An alternative straightforward cyclopropanation protocol using a catalytic amount of 2,2,6,6-tetramethylpiperidine (TMP) allows for a convenient (1 g-7.5 kg) synthesis of bicyclo[3.1.0]-hexan-2-ol and other bicyclic adducts. The synthetic utility of this chemistry has been demonstrated in a concise asymmetric synthesis of (+)-β-cuparenone. The related unsaturated chlorohydrins also undergo intramolecular cyclopropanation via in situ epoxide formation.
Intramolecular cyclopropanation of unsaturated terminal aziridines
Hodgson, David M.,Humphreys, Philip G.,Ward, John G.
, p. 995 - 998 (2007/10/03)
Regio- and stereoselective deprotonation of bishomoallylic terminal N-Bus (Bus = tert-butylsulfonyl)-protected aziridines generate aziridinyl anions that undergo diastereoselective Intramolecular cyclopropanation giving trans-2-aminobicyclo[3.1.0]hexanes in good to excellent yields.
