51097-60-0Relevant academic research and scientific papers
RuO4-mediated oxidative polycyclization of linear polyenes. A new approach to the synthesis of the bis-THF diol core of antitumour cis-cis adjacent bis-THF annonaceous acetogenins
Piccialli, Vincenzo,Caserta, Teresa,Caruso, Lucia,Gomez-Paloma, Luigi,Bifulco, Giuseppe
, p. 10989 - 11007 (2006)
The RuO4-catalyzed oxidative polycyclization of some selected linear polyenes, possessing a repetitive 1,5-diene structural motif, has been investigated. The all-trans triene (E,E,E)-acetic acid henicosa-2,6,10-trienyl ester gave the expected bis-tetrahydrofuranyl diol product possessing a threo-cis-threo-cis-threo relative configuration, along with a mixture of the corresponding bis-THF ketols. These compounds can be seen as useful intermediates in the synthesis of the bis-THF diol core of adjacent bis-THF antitumour acetogenins possessing a threo-cis-threo-cis-erythro relative configuration, such as rolliniastatiin-1, membranacin, rollimembrin and membrarollin. Oxidation of the related all-trans tetraene (E,E,E,E)-acetic acid pentacosa-2,6,10,14-tetraenyl ester stops at the second cyclization step giving a mixture of a threo-cis-threo-cis-threo bis-THF diol and the corresponding ketol products. Oxidation of the triene (E,Z,E)-acetic acid 12-acetoxy-dodeca-2,6,10-trienyl ester stops at the monocyclization level failing to give bis-cyclized products, as previously observed for the related isoprenoid triene (E,Z)-farnesyl acetate. This result confirms the difficulty of closing a second THF ring when the central double bond of the triene possesses a cis configuration. Based on the collected results, a plausible model is proposed that both explains the observed cis/trans stereoselectivity for each ring-closing step in these processes, and rationalize the stereochemical course of the previously studied polycyclization of the isoprenoid polyenes (E,E)-farnesyl acetate, geranylgeranyl acetate and squalene.
Identification of in situ flower volatiles from kiwifruit (Actinidia chinensis var. deliciosa) cultivars and their male pollenisers in a New Zealand orchard
Twidle, Andrew M.,Suckling, David M.,Seal, Alan G.,Fedrizzi, Bruno,Pilkington, Lisa I.,Barker, David
, p. 61 - 69 (2017/05/31)
In situ flower volatiles from six kiwifruit cultivars (Actinidia chinensis var. deliciosa); ‘Hayward’, ‘Chieftain’, ‘M56’, ‘Zes007’ (Green11), ‘M36’, and ‘M43’ were collected by dynamic headspace sampling. Forty-five compounds were detected in the headspace of the flowers, with straight chain hydrocarbons and terpenes accounting for >98% of the volatiles emitted quantitatively across the six cultivars. Of these hydrocarbons, (3Z,6Z,9Z)-heptadecatriene is reported for the first time from a floral source while (8Z)-hexadecene and (9Z)-nonadecene are reported for the first time from kiwifruit flowers. All three hydrocarbons were verified by synthesis. Quantitative comparison of the six honey bee perceived compounds from the headspace of the cultivars showed that the males ‘M36’ and ‘M43’ closely matched the female cultivar Green11 that they are used to pollinate. Males ‘M56’ and ‘Chieftain’ were not as closely matched to the female cultivar ‘Hayward’ that they are used to pollinate. The male ‘M56’ in particular differed significantly from the female ‘Hayward’ in four of the six honey bee perceived compounds.
Regioselective Cleavage of Electron-Rich Double Bonds in Dienes to Carbonyl Compounds with [Fe(OTf)2(mix-BPBP)] and a Combination of H2O2 and NaIO4
Spannring, Peter,Yazerski, Vital A.,Chen, Jianming,Otte, Matthias,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.,Klein Gebbink, Robertus J. M.
, p. 3462 - 3466 (2015/08/06)
A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. The combination of an Fe-based catalyst, [Fe(OTf)2(mix-BPBP)], and the oxidants H2O2 and NaIO4 can discriminate between electronically different double bonds and oxidatively cleave the electron-rich bond in dienes to yield aldehydes and ketones in a regioselective manner. The reaction requires mild conditions (0-50 C) and short reaction times (70 min).
ACYCLIC ALKENES VIA OZONOLYSIS OF MULTI-UNSATURATED CYCLOALKENES
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Paragraph 00117-00118, (2015/02/02)
A method of making a compound of formula (IIa) by selective ozonolysis of a compound of formula (I) is provided, wherein A is a C6-C10 alkene chain with at least one double bond, R1 is a C1-C10 alkyl, and R3 is an oxygen-containing functional group.
Force-reactivity property of a single monomer is sufficient to predict the micromechanical behavior of its polymer
Akbulatov, Sergey,Tian, Yancong,Boulatov, Roman
supporting information; experimental part, p. 7620 - 7623 (2012/06/30)
We demonstrate an accurate prediction of the micromechanical behavior of a single chain of cyclopropanated polybutadiene, which is governed by rapid isomerization of the cyclopropane moieties at ～1.2 nN, from the force-rate correlation of this reaction measured in a small series of increasingly strained macrocycles. The data demonstrate that a single physical quantity, force, uniquely defines the dynamics across length scales from >100 to 1 nm and that strain imposed through molecular design and that imposed by micromanipulation techniques have equivalent effects on the kinetics of a chemical reaction. This represents a new method of screening potential monomers for applications in stress-responsive materials that could also facilitate atomistic interpretations of single-molecule force experiments.
Enantioselective haloetherification by asymmetric opening of meso -halonium ions
Hennecke, Ulrich,Mueller, Christian H.,Froehlich, Roland
supporting information; scheme or table, p. 860 - 863 (2011/05/03)
A new approach to enantioselective haloetherification reactions via desymmetrization of in situ-generated meso-halonium ions is described. The combination of N-haloamides as a halogen source and sodium salts of chiral phosphoric acids as catalysts can be used for the cyclization of symmetrical ene-diol substrates, yielding the haloetherification products under practical conditions in enantioenriched form.(Figure Presented)
Monotelechelic poly(oxa)norbornenes by ring-opening metathesis polymerization using direct end-capping and cross-metathesis
Matson, John B.,Grubbs, Robert H.
experimental part, p. 213 - 221 (2011/10/01)
Two different methodologies for the synthesis of monotelechelic poly(oxa)norbornenes prepared by living ring-opening metathesis polymerization (ROMP) are presented. The first method, termed direct end-capping, is carried out by adding an internal ciss-olefin terminating agent (TA) to the reaction mixture immediately after the completion of the living ROMP reaction. The second method relies on crossmetathesis (CM) between a methylene-terminated poly(oxa)norbornene and a cis-olefin TA mediated by the ruthenium olefin metathesis catalyst (H2IMeS)(Cl)2Ru(CH-o-OiPrC 6H4) (H2IMeS = 1,3-dimesitylimidazolidine-2- ylidene). TAs containing various functional groups, including alcohols, acetates, bromides, a-bromoesters, thioacetates, N-hydroxysuccinimidyl esters, and Boc-amines, as well as fluorescein and biotin groups, were synthesized and tested. The direct end-capping method typically resulted in > 90% endfunctionalization efficiency, while the CM method was nearly as effective for TAs without polar functional groups or significant steric bulk. End-functionalization efficiency values were determined by 1H NMR spectroscopy.
Cyclopropenation of alkylidene carbenes derived from α-silyl ketones
Li, Jingwei,Sun, Chunrui,Lee, Daesung
supporting information; experimental part, p. 6640 - 6641 (2010/07/04)
A new cyclopropanation reaction involving Cα-Si bond insertion of alkylidene carbenes derived from α-silyl ketones has been developed. This unprecedented alkylidene carbene reactivity features excellent selectivity for insertion into Cα-Si bonds rather than insertion into Cγ-H bonds or addition to,δ-double or -triple bonds. The selectivity trend clearly indicates that the α-oxygen in the tether significantly promotes Cγ-H insertion, although the Cα-Si bond insertion still competes effectively.
A tandem ring-closing metathesis cleavable linker system for solid-phase oligosaccharide synthesis
Timmer, Mattie S. M.,Codée, Jeroen D. C.,Overkleeft, Herman S.,Van Boom, Jacques H.,Van Der Marel, Gijsbert A.
, p. 2155 - 2158 (2007/10/03)
A novel triene linker system, that can be cleaved by a tandem ring-closing metathesis (RCM) reaction, is presented. The tandem RCM cleavage, that regenerates the active ruthenium catalyst without the need of additives like ethylene, proceeded very clean and fast to liberate cyclopent-2-enyl mannosides from the solid support. A cyclopent-2-enyl mannoside was isomerized to the corresponding vinyl ether glycoside, which could be readily deprotected by iodine-mediated hydrolysis.
1,2-O-Isopropylidene-5-alkene templates for the synthesis of oligo-tetrahydrofurans
Dabideen, Darrin,Ruan, Zheming,Mootoo, David R
, p. 2077 - 2084 (2007/10/03)
The highly functionalized THF 4 was prepared in eight steps from 2,5-cyclooctadiene. The key step in this synthesis was a novel desymmetrization reaction involving the iodoetherification of the C2 symmetric bis-isopropylidene alkene 6 to THF 4. The versatility of 4 was demonstrated by its conversion to bis-THF 3, a known precursor for trilobacin, and to the tris-THF-lactone 5, a potential relay compound for cyclic polyether analogues.
