- CH3ReO3/H2O2 in room temperature ionic liquids: An homogeneous recyclable catalytic system for the Baeyer-Villiger reaction
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The Baeyer-Villiger oxidation of cyclic ketones can be effected by methyltrioxorhenium/hydrogen peroxide in the ionic liquid [bmim]BF4. After simple extraction of the lactone with diethyl ether, the catalyst can be repeatedly recycled and efficiently reused for the lactonisation process in the same reaction medium.
- Bernini, Roberta,Coratti, Antonietta,Fabrizi, Giancarlo,Goggiamani, Antonella
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Read Online
- Acceptorless dehydrogenative lactonization of diols by Pt-loaded SnO2 catalysts
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We report herein a new heterogeneous catalytic system for dehydrogenative lactonization of various diols under solvent-free and acceptor-free conditions using 1 mol% of Pt-loaded SnO2, providing the first successful example of acceptorless lactonization of 1,6-hexanediol to ε-caprolactone by a heterogeneous catalyst. This journal is
- Touchy, Abeda Sultana,Shimizu, Ken-Ichi
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Read Online
- A volatile lactone of Hymenoscyphus pseudoalbidus, pathogen of European ash dieback, inhibits host germination
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The largely unknown secondary metabolism of the plant pathogenic fungus Hymenoscyphus pseudoalbidus was investigated by use of the CLSA method. A set of volatile lactones was identified by GC/MS. The lactones were synthesized and used in bioassays in which one of the compounds was found to be a strong germination inhibitor for ash seeds, causing necroses in the plant tissue. The largely unknown secondary metabolism of the plant pathogenic fungus Hymenoscyphus pseudoalbidus was investigated by use of the closed-loop stripping apparatus (CLSA) method. A set of volatile lactones was identified by GC/MS. The lactones were synthesized and used in bioassays in which one of the compounds was found to be a strong germination inhibitor for ash seeds.
- Citron, Christian A.,Junker, Corina,Schulz, Barbara,Dickschat, Jeroen S.
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- Photobiocatalytic alcohol oxidation using LED light sources
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The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported. This in situ NAD+ regeneration system can be used to promote biocatalytic, enantioselective oxidation reactions. Compared to the traditional use of white light bulbs this method enables very significant reductions in energy consumption and CO2 emission.
- Rauch,Schmidt,Arends,Oppelt,Kara,Hollmann
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Read Online
- Asymmetric conjugate addition of grignard reagents to pyranones
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An efficient enantioselective synthesis of lactones was developed based on the catalytic asymmetric conjugate addition (ACA) of alkyl Grignard reagents to pyranones. The use of 2H-pyran-2-one for the first time in the ACA with Grignard reagents allows for a variety of further transformations to access highly versatile building blocks such as β-alkyl substituted aldehydes or β-bromo-γ-alkyl substituted alcohols with excellent regio-and stereoselectivity.
- Mao, Bin,Fa?anás-Mastral, Martín,Feringa, Ben L.
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- PROCESS FOR THE PREPARATION OF (Z,2E)-5-[1-(4-CHLOROPHENYL)PYRAZOL-3-YL]OXY-2-METHOXYIMINO-N,3-DIMETHYL-PENT-3-ENAMIDE DERIVATIVES
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The present invention relates to a process for the preparation of (Z,2E)-5-[1-(4- chlorophenyl)pyrazol-3-yl]oxy-2-methoxyimino-N,3-dimethyl-pent-3-enamide derivatives suitable for use, e.g., as active ingredients, which have microbiocidal activity, in particular, fungicidal activity.
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(2021/04/30)
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- Ruthenium-Promoted Acceptorless and Oxidant-Free Lactone Synthesis in Aqueous Medium
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Ruthenium-catalyzed formation of lactones from diols in aqueous medium has been demonstrated. 1,3,5-Triazaphosphaadamantane (PTA) included water-soluble ruthenium complexes [RuCl 2 (PPh 3)(2,6-Py-(CH 2 -PTA) 2 ]·2Br and [RuCl 2 (PPh 3) 2 (2-PyCH 2 PTA)]·Br in the presence of KOH were found to be efficient for the synthesis of lactones from diols. The reported synthetic protocol is green as it uses water as solvent, avoids the use of any hydrogen acceptor/oxidant, and produces hydrogen as the only side product. Mechanistic studies revealed that lactone formation involved aldehyde intermediate and followed dehydrogenative pathway.
- Bhatia, Anita,Kannan, Muthukumar,Muthaiah, Senthilkumar
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supporting information
p. 721 - 725
(2019/03/26)
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- Stereoselective synthesis of alicyclic ketones: A hydrogen borrowing approach
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A highly diastereoselective annulation strategy for the synthesis of alicyclic ketones from diols and pentamethylacetophenone is described. This process is mediated by a commercially available iridium(III) catalyst, and provides efficient access to a wide range of cyclopentane and cyclohexane products with high levels of stereoselectivity. The origins of diastereoselectivity in the annulation reaction have been explored by a series of control experiments, which provides an explanation for how each stereocentre around the newly forged ring is controlled.
- Armstrong, Roly J.,Akhtar, Wasim M.,Frost, James R.,Christensen, Kirsten E.,Stevenson, Neil G.,Donohoe, Timothy J.
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supporting information
(2019/11/13)
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- Stereoselective Synthesis of Cyclohexanes via an Iridium Catalyzed (5 + 1) Annulation Strategy
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An iridium catalyzed method for the synthesis of functionalized cyclohexanes from methyl ketones and 1,5-diols is described. This process operates by two sequential hydrogen borrowing reactions, providing direct access to multisubstituted cyclic products with high levels of stereocontrol. This methodology represents a novel (5 + 1) strategy for the stereoselective construction of the cyclohexane core.
- Akhtar, Wasim M.,Armstrong, Roly J.,Frost, James R.,Stevenson, Neil G.,Donohoe, Timothy J.
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supporting information
p. 11916 - 11920
(2018/09/27)
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- Phosphine-pyridonate ligands containing octahedral ruthenium complexes: Access to esters and formic acid
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The preparation of three well-defined ruthenium complexes arising from phosphine-pyridon-e/-ate ligands is described. Solvent dependent Lewis acidic species formation was observed with these complexes. Selective formation of acetals or esters from primary alcohols was observed in the presence of these catalysts. Preliminary evaluation of these complexes in the base free hydrogenation of carbon dioxide is also reported.
- Sahoo,Jiang,Bruneau,Sharma,Suresh,Roisnel,Dorcet,Achard
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p. 3492 - 3498
(2017/08/23)
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- METHODS OF FORMING DIOL COMPOUNDS
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Methods of forming a C4 to C7 diol compound, the methods including a first step of reacting a C4 to C7 dicarboxylic acid with hydrogen (H2) gas on a first heterogeneous catalyst at a first temperature and a first pressure to form a C4 to C7 lactone; and a subsequent step of reacting the lactone with hydrogen (H2) gas on a second heterogeneous catalyst at a second temperature and a second pressure, wherein the second temperature is lower than the first temperature. Also disclosed are methods of forming a solvent, the methods including reacting a C4 to C7 dicarboxylic acid with hydrogen (H2) gas on a first heterogeneous catalyst at a first temperature and a first pressure to form a solvent. Further disclosed herein are methods that include reacting mevalonolactone with hydrogen (H2) gas on a second heterogeneous catalyst at a second temperature and a second pressure to form a diol compound.
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Paragraph 0093
(2017/11/06)
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- LYMPH DIRECTING PRODRUGS
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H:\dar\Interwoven\NRPortbl\DCC\DAR\8230712_1.doc-12/08/2015 Abstract The present invention relates to compounds and their uses, in particular, compounds in the form of prodrugs that promote transport of a pharmaceutical agent to the lymphatic system and subsequently enhance release of the parent drug.
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(2016/02/29)
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- BIOSYNTHETIC PATHWAYS AND PRODUCTS
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This disclosure describes biosynthesized compounds including anhydromevalonolactone and β-methyl-δ-valerolactone. This disclosure further describes biosynthetic methods for making these compounds. In some embodiments, the biosynthetic methods can include a combination of biosynthesis and chemical steps to produce β-methyl-δ-valerolactone. Finally, this disclosure described recombinant cells useful for the biosynthesis of these compounds.
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Paragraph 0152-0155
(2017/01/09)
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- Multi-arm polymeric alkanoate conjugates
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Among other aspects, provided herein are multi-armed polymer conjugates comprising an alkanoate-linker, compositions comprising such conjugates, and related methods of making and administering the same. Methods of treatment employing such conjugates and related uses are also provided. The conjugates are prepared with high drug loading efficiencies.
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Page/Page column 61
(2016/01/20)
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- Aldol Additions of Titanium and Boron Enolates of Achiral and Chiral δ-Lactones to Achiral Model Aldehydes: Simple and Induced Diastereoselectivities
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We studied the steric course of aldol additions of CpTiCl2 (novel) or Bu2B enolates of the unsubstituted δ-lactone and of the four monomethylated δ-lactones to isobutyraldehyde, crotonaldehyde, and para-bromobenzaldehyde. The titanium enolates reacted syn-selectively with >95:5 ds in most cases. The boron enolates reacted anti-selectively without exception (ds = 98:2 to 92:8). These selectivities paired with a preferred trans-orientation of the α-hydroxyalkyl substituents relative to the lactone's β- or γ-methyl group and with a preferred cis-orientation relative to the lactone's δ-methyl group. Our preparation of γ-methyl-δ-lactone (20) features a tandem glycol cleavage/lactol → lactone conversion with cat. TEMPO/stoichiom. PhI(OAc)2, which we believe is novel. Aldol additions of CpTiCl2 and Bu2B enolates of δ-lactone and its monomethyl derivatives to model aldehydes were studied. The CpTiCl2 enolates reacted syn-selectively (ds >95:5), the Bu2B enolates anti-selectively (ds up to 98:2). The α-hydroxyalkyl groups were oriented trans relative to the lactone's β- or γ-methyl group but cis relative to the lactone's δ-methyl group.
- Weber, Fabian,Becker, Fabian,Keller, Manfred,Hillebrecht, Harald,Brückner, Reinhard
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supporting information
p. 7892 - 7918
(2015/12/24)
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- From diols to lactones under aerobic conditions using a laccase/TEMPO catalytic system in aqueous medium
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An efficient catalytic system to oxidize quantitatively aliphatic diols using Trametes versicolor laccase and TEMPO has been developed in aqueous medium. Oxidations have occurred in a non-stereoselective fashion but with complete regio- and/or monoselectivity, obtaining lactones with excellent purity after simple extraction. This catalytic system has been demonstrated to be scalable, compatible with the presence of a variety of functionalities, and also allowed the successful enzyme recycling using a laccase-cross-linked enzyme aggregates (CLEA) preparation.
- Gotor-Fernandez, Vicente,Diaz-Rodriguez, Alba,Lavandera, Ivan,Kanbak-Aksu, Seda,Sheldon, Roger A.,Gotor, Vicente
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supporting information
p. 3405 - 3408
(2013/02/22)
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- Chiral hetero- and carbocyclic compounds from the asymmetric hydrogenation of cyclic alkenes
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Several types of chiral hetero- and carbocyclic compounds have been synthesized by using the asymmetric hydrogenation of cyclic alkenes. N,P-Ligated iridium catalysts reduced six-membered cyclic alkenes with various substituents and heterofunctionality in good to excellent enantioselectivity, whereas the reduction of five-membered cyclic alkenes was generally less selective, giving modest enantiomeric excesses. The stereoselectivity of the hydrogenation depended more strongly on the substrate structure for the five- rather than the six-membered cyclic alkenes. The major enantiomer formed in the reduction of six-membered alkenes could be predicted from a selectivity model and isomeric alkenes had complementary enantioselectivity, giving opposite optical isomers upon hydrogenation. The utility of the reaction was demonstrated by using it as a key step in the preparation of chiral 1,3-cis-cyclohexane carboxylates. Copyright
- Verendel, J. Johan,Li, Jia-Qi,Quan, Xu,Peters, Byron,Zhou, Taigang,Gautun, Odd R.,Govender, Thavendran,Andersson, Pher G.
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p. 6507 - 6513
(2012/06/29)
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- Aerobic lactonization of diols by biomimetic oxidation
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Coming up for air: Highly efficient aerobic lactonization can be carried out by a biomimetic oxidation system based on coupled redox catalysts (ruthenium catalyst and electron transfer mediators). This system leads to a low-energy electron transfer from diol to molecular oxygen. Various diols were aerobically oxidized to the corresponding five- to nine-membered lactones in good to high yields under mild reaction conditions (see scheme).
- Endo, Yoshinori,Baeckvall, Jan-E.
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supporting information; experimental part
p. 12596 - 12601
(2011/12/03)
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- Oxidant-free lactonization of diols using a hydrotalcite-supported copper catalyst
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We newly synthesized well-crystallized hydrotalcite-supported copper nanoparticles, denoted as Cu/HT(c), which acted as a highly efficient heterogeneous catalyst for oxidant-free lactonization of various diols under liquid-phase conditions. The Cu/HT(c) catalyst could be recovered by simple filtration and reused without the significant loss of its activity and selectivity.
- Mikami, Yusuke,Ebata, Kaori,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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experimental part
p. 855 - 861
(2010/09/16)
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- Structure-activity study of new inhibitors of human betaine-homocysteine S-methyltransferase
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Betaine-homocysteine S-methyltransferase (BHMT) catalyzes the transfer of a methyl group from betaine to L-homocysteine, yielding dimethylglycine and L-methionine. In this study, we prepared a new series of BHMT inhibitors. The inhibitors were designed to mimic the hypothetical transition state of BHMT substrates and consisted of analogues with NH, N(CH3), or N(CH 3)2 groups separated from the homocysteine sulfur atom by a methylene, ethylene, or a propylene spacer. Only the inhibitor with the N(CH3) moiety and ethylene spacer gave moderate inhibition. This result led us to prepare two inhibitors lacking a nitrogen atom in the S-linked alkyl chain: (RS,RS)-5-(3-amino-3-carboxypropylthio)-3-methylpentanoic acid and (RS)-5-(3-amino-3-carboxypropylthio)-3,3-dimethylpentanoic acid. Both of these compounds were highly potent inhibitors of BHMT. The finding that BHMT does not tolerate a true betaine mimic within these inhibitors, especially the nitrogen atom, is surprising and evokes questions about putative conformational changes of BHMT upon the binding of the substrates/products and inhibitors.
- Vaněk, Václav,Budě?ínsky, Milo?,Kabeleová, Petra,?anda, Miloslav,Koz?í?ek, Milan,Han?lová, Ivona,Mládková, Jana,Brynda, Ji?í,Rosenberg, Ivan,Koutmos, Markos,Garrow, Timothy A.,Jirá?ek, Ji?í
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scheme or table
p. 3652 - 3665
(2010/04/30)
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- Supported gold nanoparticles as a reusable catalyst for synthesis of lactones from diols using molecular oxygen as an oxidant under mild conditions
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The oxidative lactonization of various diols using molecular oxygen as a primary oxidant can be efficiently catalyzed by hydrotalcite-supported Au nanoparticles (Au/HT). For instance, lactonization of 1,4-butanediol gave γ-butyrolactone with an excellent turnover number of 1400. After lactonization, the Au/HT can be recovered by simple filtration and reused without any loss of its activity and selectivity.
- Mitsudome, Takato,Noujima, Akifumi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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experimental part
p. 793 - 797
(2010/04/23)
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- Barium manganate in microwave-assisted oxidation reactions: synthesis of lactones by oxidative cyclization of diols
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Microwave irradiation of a range of diols at 150 °C in acetonitrile in the presence of three equivalents of barium manganate facilitates a novel tandem oxidation/heterocyclocondensation to give the corresponding lactone, including both small and medium ring lactones, in only one hour and in high yield without the need for chromatographic purification.
- Bagley, Mark C.,Lin, Zhifan,Phillips, David J.,Graham, Andrew E.
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experimental part
p. 6823 - 6825
(2010/04/27)
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- METHOD FOR PRODUCTION OF 3-METHYL-1,5-PENTANEDIOL
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Provided is a method for producing 3-methyl-1,5-pentanediol by hydrogenating 2-hydroxy-4-methyltetrahydropyran in the presence of a hydrogenation catalyst, characterized in that the hydrogenation is further carried out in the presence of a basic compound. By this method, in producing MPD by hydrogenation of MHP, high-purity MPD can be produced by effectively suppressing generation of by-products such as MPAE and MVL even when a known hydrogenation catalyst is used.
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(2009/02/10)
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- METHOD FOR PRODUCING 3-METHYL-1,5-PENTANEDIOL
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Provided is a method for producing 3-methyl-1,5-pentanediol by hydrogenating 2-hydroxy-4-methyltetrahydropyran in the presence of a hydrogenation catalyst, characterized in that the hydrogenation is further carried out in the presence of a basic compound. By this method, in producing MPD by hydrogenation of MHP, high-purity MPD can be produced by effectively suppressing generation of by-products such as MPAE and MVL even when a known hydrogenation catalyst is used.
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(2009/04/25)
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- In situ generation of ylides for tandem oxidation-olefination reactions of unactivated diols
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An efficient desymmetrization of diols is achieved using phosphonium salts which undergo deprotonation in the presence of a hindered amine base and manganese dioxide to produce α,β-unsaturated hydroxy esters in good yields. Georg Thieme Verlag Stuttgart.
- Phillips, David J.,Graham, Andrew E.
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p. 649 - 652
(2008/12/20)
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- ALPHA 7 NICOTINIC RECEPTOR SELECTIVE LIGANDS
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The invention relates to the design and synthesis of 3-arylidene-anabaseine compounds that exhibit enhanced selectivity toward alpha7 nicotinic receptors. The compounds are expected to be useful in treating a wide variety of conditions, including neurodegenerative conditions such as Alzheimer's Disease, neurodevelopmental diseases such as schizophrenia, and certain peripherally located inflammations mediated by macrophage infiltration.
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Page/Page column 83; 85
(2008/06/13)
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- The effect of pre-existing stereocenters in the intramolecular asymmetric Stetter reaction
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A series of disubstituted cyclopentanones have been synthesized by the intramolecular Stetter reaction. Racemic substrates containing one chiral center were used, allowing us the opportunity to observe a parallel kinetic resolution in the synthesis of 2,3- and 2,4-disubstituted cyclopentanones. The Stetter reaction of 2,5-disubstituted cyclopentanones proved to be substrate controlled, resulting in the selective formation of the cis-diasteromers with low ee.
- Reynolds, Nathan T.,Rovis, Tomislav
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p. 6368 - 6378
(2007/10/03)
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- A synthesis of 6-tributylstannyl-3,4-dihydro-2H-pyrans via coupling of enol triflates with (Bu3Sn)(Bu)Culi·liCN
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Enol triflates derived from 6- and 7-membered ring lactones (6 cases) react with (Bu3Sn)(Bu)CuLi·LiCN in THF at -78 °C to give the corresponding α-tributylstannyl cyclic enol ethers in 54-85% yield.
- Wildman, Tanya,Kocienski, Philip J.,Narquizian, Robert,Whittingham, William G.
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p. 393 - 398
(2007/10/03)
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- New strategies in carbonylation chemistry: The synthesis of δ-lactones from saturated alcohols and CO
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This paper describes the δ-carbonylation of saturated alcohols which uses a 1,5-hydrogen-transfer reaction of alkoxyl radicals and subsequent carbonylation at the δ-carbon atoms as the key. The carbonylation reactions of five classes of saturated alcohols, namely, primary alcohols having primary δ-carbons, primary alcohols having secondary δ-carbons, primary alcohols having tertiary δ-carbons, secondary alcohols having primary δ- carbons, secondary alcohols having secondary δ-carbons, were carded out, in which lead tetraacetate (LTA) was used as a one-electron oxidant to generate the alkoxyl radicals. Carbonylation of these saturated alcohols, except for primary alcohols having tertiary δ-carbons, took place to afford δ-lactones in moderate to good yields. The mechanism of the remote carbonylation likely involves (1) alkoxyl radical generation via LTA oxidation of a saturated alcohol, (2) conversion of this alkoxyl radical to a δ-hydroxyalkyl radical by a 1,5-hydrogen-transfer reaction, (3) CO trapping of the δ-hydroxyalkyl radical yielding an acyl radical, and (4) oxidation and cyclization of the acyl radical to give a δ-lactone. A metal salt-free system was also tested for a substrate derived from a tertiary alcohol having a secondary δ- carbon; the photolysis of an alkyl 4-nitrobenzenesulfenate under CO pressures gave a δ-lactone in moderate yield.
- Tsunoi, Shinji,Ryu, Ilhyong,Okuda, Tohru,Tanaka, Minoru,Komatsu, Mitsuo,Sonoda, Noboru
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p. 8692 - 8701
(2007/10/03)
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- Opening of cyclopropyl ketones with SmI2 . Synthesis of spirocyclic and bicyclic ketones by intramolecular trapping of an electrophile
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A method for the opening of cyclopropyl ketones with samarium (II) iodide followed by the intramolecular trapping of an electrophile is described. This process leads to the obtainment of functionalized spirocyclic, bicyclic, and tricyclic ketones in moderate to good yields.
- Molander, Gary A.,Alonso-Alija, Cristina
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p. 8067 - 8084
(2007/10/03)
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- Enzymes in organic synthesis, 26: Synthesis of enantiomerically enriched 2,3- and 3,4-dimethylpentan-5-olides by lipase-catalyzed regio- and enantioselective alcoholysis of cis- and trans-2,3-dimethylpentanedioic anhydrides
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The enzyme-catalyzed regio- and enantioselective alcoholysis of racemic cis- and trans-2,3-dimethylpentanedioic anhydride in the presence of Novozym 435 from Candida antarctica afforded two of the eight possible monoesters with an enantiomeric excess higher than 90%. Regioselective reductions of these monoesters with lithium borohydride or borane/dimethyl sulfide furnished four enantiomerically highly enriched dimethylpentan-5-olides, which are versatile chiral intermediates. VCH Verlagsgesellschaft mbH, 1996.
- Ozegowski, Ruediger,Kunath, Annamarie,Schick, Hans
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p. 1443 - 1448
(2007/10/03)
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- Folding strain stereocontrol in cyclohexane ring formation by means of an intramolecular ester enolate alkylation reaction
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Diastereoselectivity in the cyclization of ethyl 7-bromo-2-methylheptanoates with an additional substituent at various positions in the chain, by LDA treatment, was investigated in connection with the concept of folding strain stereocontrol. Cyclization of 3-, 4-, and 6-methyl-substituted substrates revealed high selectivity, which demonstrates the prevalence of folding strain stereocontrol and the usefulness of this approach for stereoselective ring construction. In particular, reactions of the latter two substrates resulted in the stereodivergent preparation of diastereomeric 1,3-dimethylcyclohexanecarboxylates. In the case of the 5-methyl-substituted substrate, the selectivity of ring closure was only moderate. 1H and 13C NMR spectroscopic data were useful for determining the conformation of 1-methylcyclohexanecarboxylate derivatives. The origin of the diastereoselectivity was examined through the qualitative comparison of the strain in the diastereomeric folding in the transition state. Various factors that might affect stereoselectivity were examined in the cyclization of 5-substituted substrates to better understand this concept. As predicted, the selectivity increased as the substituent became bulkier: Ph Me ≈ Et ≤ i-Pr t-Bu. The effects of other factors - solvent, base counter cation, and leaving group - on selectivity agree with results predicted from the reactivity-selectivity relationship.
- Tokoroyama, Takashi,Kusaka, Hisashi
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p. 2487 - 2502
(2007/10/03)
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- Oxidation of Diols with Sodium Bromite Trihydrate in Organic Solvents in the Presence of Alumina
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The title oxidation of diols with two primary hydroxy groups (symmetrical diols) and those with both a primary and a secondary hydroxy group (unsymmetrical diols) gives the corresponding lactones or the hydroxy ketones, being dependent upon the types of diols.
- Morimoto, Takashi,Hirano, Masao,Iwasaki, Keiko,Ishikawa, Takashi
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- A convenient lactonization of diols to γ- and δ-lactones catalyzed by transition metals polyhydrides
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Transition metal polyhydrides-catalyzed oxidative condensation of diols to 5 and 6-ring lactones was studied.The regioselective dehydrogenation of unsymmetrically substituted 1,4-diols gave β- or γ-substituted γ-lactones in high yields.The mechanism of dehydrogenation under neutral and mild conditions was discussed.
- Lin, Yingrui,Zhu, Xianchao,Zhou, Yuefen
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p. 269 - 274
(2007/10/02)
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- Oxidation of Alcohols with Peracetic Acid in Ethyl Acetate in the Presence of Sodium Bromide
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Aliphatic primary alcohols and 1,ω-diols were oxidized to the dimeric esters and lactones, respectively, by peracetic acid in ethyl acetate in the presence of sodium bromide under mild conditions.Aliphatic secondary and benzylic alcohols were converted smoothly to the corresponding carbonyl compounds by the same system.
- Morimoto, Takashi,Hirano, Masao,Hamaguchi, Takayoshi,Shimoyama, Masahide,Zhuang, Xiumin
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p. 703 - 706
(2007/10/02)
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- An Useful Synthetic Method for 3-Substituted δ-Lactones. Synthesis of (+/-)-Secocrispiolide
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2-Phenylthio-2-penten-5-olide (1) acted as a reactive Michael acceptor toward some typical carbon nucleophiles to give 3-substituted 2-phenylthio-5-pentanolides (2) which were convertible both to 3-substituted 5-pentanolides by reductive desulfurization and to 3-substituted 2-penten-5-olides by sulfenic acid syn elimination of the sulfoxides 4 derived from 2.The Pummerer rearrangement of 4 provided 3-substituted 2-phenylthio-2-penten-5-olides and/or 2-hydroxy-2-penten-5-olides. (+/-)-Secocrispiolide was synthesized via the adduct obtained by the Michael reaction of 1 with the Grignard reagent prepared from 2,6-dimethylbenzyl bromide and magnesium.
- Kato, Michiharu,Ouchi, Akihiko,Yoshikoshi, Akira
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p. 1479 - 1486
(2007/10/02)
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- Hydroformylation of 3-methyl-3-buten-1-ol and analogs thereof and use of such hydroformylation products
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There is disclosed a method of hydroformylating 3-methyl-3-buten-1-ol and analogs thereof with carbon monoxide and hydrogen in the presence of a rhodium compound free from modification by a ligand containing an element belonging to the group V of the periodic table as well as a method of producing 3-methylpentane-1,5-diol and β-methyl-δ-valerolactone using such hydroformylation product.
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- 7-oxabicycloheptane substituted oxa prostaglandin analgos useful in the treatment of thrombolytic disease
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7-Oxabicycloheptane substituted oxo prostaglandin analogs are provided having the structural formula STR1 wherein R is hydrogen, lower alkyl, alkali metal or trihydroxymethylaminomethane, R1 is lower alkyl, aryl, aralkyl, cycloalkyl or cycloalkylalkyl, R2 is hydrogen or lower alkyl, A is --CH=CH-- or --(CH2)2 --, n is 1 to 4, and m is 1 to 8, and including all stereoisomers thereof. The compounds are cardiovascular agents useful, for example, in the treatment of thrombolytic disease.
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- Cyclisation des alcools δ-alleniques par le nitrate d'argent ou les sels mercuriques. Synthese d'α-alcenyl-2 tetrahydropyrannes
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Eight diversely substituted δ-allenic alcohols have been synthesized by using three different methods for the formation of the allenic linkage.When treated with silver nitrate or mercuric salts, these alcohols are transformed in fairly good yields into α-alkenyl-2 tetrahydropyrans.In addition to its regioselectivity in the formation of the heterocycle this reaction shows in certain cases a high stereoselectivity.Alcohols monosubstituted on the thermal allenic carbon lead to more than 90percent of the E product whereas the 2,4 or 2,6 disubstituted tetrahydropyrans are obtained in predominantly the Z configuration.
- Audin, Patrick,Doutheau, Alain,Gore, Jacques
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p. 297 - 306
(2007/10/02)
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- Polystyrene-Bound Phenylselenic Acid: Catalytic Oxydations of Olefins, Ketones, and Aromatic Systems
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A new synthesis of polystyrene-bound phenylselenic acid, from reaction of mercurated polystyrene and selenium dioxide, is described.A triphasic system of the polymer (in catalytic amounts), aqueous hydrogen peroxide, and dichloromethane is shown to be an effective medium for the conversion of olefins into trans diols and ketones into esters.A biphasic system of the polymer and tert-butyl hydroperoxide in refluxing chloroform effects the selective oxidation of benzylic alcohols to the carbonyl species.In a similar catalytic system hydroxy aromatic compounds can be converted into quinones.Conversion of 1,5-dihydroxynaphthalene into juglone can be realized in 70percent yield.
- Taylor, Richard T.,Flood, Lawrence A.
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p. 5160 - 5164
(2007/10/02)
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