- Regioselective Hydrogenation of Itaconic Acid to Γ-Isovalerolactone by Transition-Metal Nanoparticle Catalysts
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Current methods for hydrogenation of bio-derived itaconic acid (IA) lead to a mixture of isomeric lactone products. Transition-metal nanoparticles (TM-NPs), in situ-generated through thermolysis of TM(0) (Ru, Fe, W, Cr) carbonyls, in particular Ru-NPs, were found to catalyze regioselective hydrogenation of IA by syngas (2 H2/CO) into γ-isovalerolactone (GiVL) in approximately 70 % isolated yield. Key sustainability features of this new route include: a one-pot direct transformation of bio-renewable IA into value-added GiVL selectively, use of inexpensive and renewable syngas in aqueous solution, and development of a supported recyclable NP catalyst system, Al2O3-Ru-NPs.
- Gowda, Ravikumar R.,Chen, Eugene Y.-X.
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- Extension of the Eschenmoser sulfide contraction/iminoester cyclization method to the synthesis of tolyporphin chromophore
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Tolyporphin chromophore 2 has been synthesized by performing a double-retroaldol/oxidation sequence on an octahydroporphyrin precursor 18 prepared by using the Eschenmoser sulfide-contraction/iminoester-condensation method.
- Minehan, Thomas G.,Kishi, Yoshito
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- TETRAKIS(1-METHYLCYCLOPROPYL)ETHYLENE IN FOUR STEPS FROM α-METHYL-γ-BUTYROLACTONE
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A short and efficient synthesis of bis(1-methylcyclopropyl)ketone (6) via the spiro-acetal 4 from α-methyl-γ-butyrolactone (1) has been found, and reductive dimerization of 6 by McMurry coupling yields tetrakis(1-methylcyclopropyl)ethylene (7) in competition with ring-opened products (8 and 9).
- Boehrer, Gerald,Knorr, Rudolf
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- Synthesis of butyrolactones by nickel-catalyzed reductive cyanation of alkynols in water
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One-pot catalytic synthesis of butyrolactones from alkynols under mild conditions is described here. The methodology involves the use of the K 2[Ni(CN)4]/NaBH4 system in presence of KCN and water. According to the experimental evidences, a possible mechanism pathway is suggested, which involves the nickel-catalyzed reductive cyanation of alkynol, followed by nitrile hydration, reduction of double bond and lactonization.
- García Gutiérrez, José Luis,Jiménez-Cruz, Federico,Espinosa, Noé Rosas
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- Branched Diol Monomers from the Sequential Hydrogenation of Renewable Carboxylic Acids
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A prominent challenge in replacing petrochemical polymers with bioderived alternatives is the efficient transformation of biomass into useful monomers. In this work, we demonstrate a practical process for the synthesis of multifunctional alcohols from five- and six-carbon acids using heterogeneous catalysts in aqueous media. Design of this process was guided by thermodynamic calculations, which indicate the need for two sequential high-pressure hydrogenations: one, reduction of the acid to a lactone at high temperature; two, further reduction of the lactone to the corresponding diol or triol at low temperature. For example, the conversion of mesaconic acid into (α or β)-methyl-γ-butyrolactone was achieved with 95 % selectivity at a turnover frequency of 1.2 min?1 over Pd/C at 240 °C. Subsequent conversion of (α or β)-methyl-γ-butyrolactone into 2-methyl-1,4-butanediol was achieved with a yield of 80 % with Ru/C at 100 °C. This process is an efficient method for the production of lactones, diols, and triols, all valuable monomers for the synthesis of bioderived branched polyesters.
- Spanjers, Charles S.,Schneiderman, Deborah K.,Wang, Jay Z.,Wang, Jingyu,Hillmyer, Marc A.,Zhang, Kechun,Dauenhauer, Paul J.
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- Esterification and ketalization of levulinic acid with desilicated zeolite β and pseudo-homogeneous model for reaction kinetics
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To maximize the production of esters (E), keto (K) and keto-ester (KE) by esterification and ketalization of levulinic acid (LA) has been reacted using diols such as 1,2-propane diol (PDOL),1,2-ethane diol (EDOL), and 1,2,3-propane triol or glycerol (TRIOL) with desilicated Hβ. This work aims to assess the conversion and selectivity for the production of esters using conventional and microwave-irradiated (MWI) reactors. Catalysts characterizations were performed using NH3-temperature programme desorption, Brunauer, Emmett and Teller surface area (BET), Barrett, Joyner, and Halenda (BJH), scanning electron microscope, transmission electron microscope, and dynamic light scattering. Operating parameters such as reaction temperature (170–180°C), reaction time (20–80?min), feed composition (LA:PDOL/EDOL/TRIOL, 1:8/10/12), and microwave energy (300–500 watt) have been systematically investigated. Note that 99–100% conversion was achieved with the product selectivity of E (40%), K (30%), and KE (30%) with1,2-EDOL; E (56%), K (2%), and KE (17%) with 1,2-PDOL; E (69%), K(0%), and KE (22%) with TRIOL using D-Hβ as a solid catalyst in an MWI reactor. Reaction paths and kinetics were studied using pseudo-homogeneous (PH) model.
- Umrigar, Vaishali,Chakraborty, Mousumi,Parikh, Parimal
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- Cobalt-Mediated Switchable Catalysis for the One-Pot Synthesis of Cyclic Polymers
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A cobalt salen pentenoate complex [salen=(R,R)-N,N′-bis(3,5-di-tertbutylsalicylidene)-1,2-cyclohexanediamine] is rationally designed as the catalyst for the ring-opening copolymerization (ROCOP) of epoxides/anhydrides/CO2. Via migratory insertion of carbon monoxide (CO) into the Co?O bonds, the ROCOP-active species α-alkene-ω-O-CoIII(salen) can be rapidly and quantitatively transformed into α-alkene-ω-O2C-CoIII(salen) telechelic linear precursors. Upon dilution of reaction mixtures, the homolytic cleavage of Co?C bonds induced by visible light generates α-alkene acyl radicals that spontaneously undergo intramolecular radical addition to afford organocobalt-functionalized cyclic polyesters and CO2-based polycarbonates with excellent regioselectivity. The cyclic products can either react with radical scavengers to generate metal-free cyclic polymers or serve as photo-initiators for organometallic-mediated radical polymerization (OMRP) to produce tadpole-shaped copolymers.
- Lam, Jacky W. Y.,Liao, Can,Tang, Ben Zhong,Wang, Xianhong,Wang, Yong,Xie, Xiaolin,Zhao, Yajun,Zhou, Xingping,Zhu, Shuaishuai
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- A NEW TEMPLATE of MITSUNOBU ACYLATE CLEAVABLE in NONALKALINE CONDITIONS
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The Mitsunobu inversion is one of the reliable methods for stereospecific substitution of chiral alcohols, but its deacylation step has limited the substrate scope. Here, we propose a new template of the Mitsunobu acylate that can be deacylated in non-alkaline treatments. The 3,4-dihydroxy-2-methylenebutanoate was selected as a template structure, and its acetonide- or bisTBS derivatives were synthesized. The latter especially showed excellent inversion efficiency (up to >99% ee) and good elimination performance for a series of secondary alcohols in near-neutral conditions. The results demonstrated the applicability of the new template for the substrates labile in alkaline conditions, such as a-hydroxyesters.
- Sai, Yusuke,Sakakibara, Yoshimichi,Shigetomi, Kengo,Ubukata, Makoto,Uraki, Yasumitsu
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p. 140 - 158
(2022/01/08)
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- Selective hydrogenolysis of 2-furancarboxylic acid to 5-hydroxyvaleric acid derivatives over supported platinum catalysts
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The conversion of 2-furancarboxylic acid (FCA), which is produced by oxidation of furfural, to 5-hydroxyvaleric acid (5-HVA) and its ester/lactone derivatives with H2 was investigated. Monometallic Pt catalysts were effective, and other noble metals were not effective due to the formation of ring-hydrogenation products. Supports and solvents had a small effect on the performance; however, Pt/Al2O3 was the best catalyst and short chain alcohols such as methanol were better solvents. The optimum reaction temperature was about 373 K, and at higher temperature the catalyst was drastically deactivated by deposition of organic materials on the catalyst. The highest yield of target products (5-HVA, δ-valerolactone (DVL), and methyl 5-hydroxyvalerate) was 62%, mainly obtained as methyl 5-hydroxyvalerate (55% yield). The byproducts were mainly ring-hydrogenation compounds (tetrahydrofuran-2-carboxylic acid and its ester) and undetected ones (loss of carbon balance). The catalyst was gradually deactivated during reuses even at a reaction temperature of 373 K; however, the catalytic activity was recovered by calcination at 573 K. The reactions of various related substrates were carried out, and it was found that the O-C bond in the O-CC structure (1,2,3-position of the furan ring) is dissociated before CC hydrogenation while the presence and position of the carboxyl group (or methoxy carbonyl group) much affect the reactivity.
- Asano, Takehiro,Takagi, Hiroshi,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi
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p. 6133 - 6145
(2019/11/20)
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- A aqueous phase catalytic itaconic acid hydrogenation process for preparing butyl lactone method (by machine translation)
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The invention relates to a process for preparing aqueous phase catalytic itaconic acid butyl lactone of hydrogenation method, relates in particular to a itaconic acid aqueous phase hydrogenation process for preparing butyl lactone (α - methyl - γ - butyrolactone and β - methyl - γ - butyrolactone) synthesis process and corresponding hydrogenation metal catalyst preparation and its in the reaction applied research. Butyl lactone is a molecule of simple structure but the synthetic route complex important organic compounds, widely applied to the resin solvent, lubricant, plasticizer, non-ionic surface-active agent of the gelling agent, lactone additives of leaded gasoline, synthetic fiber of cellulose ester such as dyeing and synthesizing various related compounds such as pyrrolidone intermediate. The invention preparation of Ru-based catalyst, in mild aqueous phase under the reaction conditions, the itaconic acid catalytic hydrogenation reaction to prepare the butyl lactone, conversion can be 99%, butyl lactone yield can be up to 50%, the catalyst can be recycled many times. (by machine translation)
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Paragraph 0028; 0029; 0030
(2019/05/16)
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- METHOD FOR REDUCTION OF ORGANIC MOLECULES
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A method for the reduction organic molecules comprising a Ruthenium-Triphosphine complex with aromatic ligands at the phosphors which are ortho or meta substituted.
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Paragraph 0050; 0052; 0053; 0054; 0055
(2018/02/06)
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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 0115
(2017/11/06)
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- Direct hydrogenation of biobased carboxylic acids mediated by a nitrogen-centered tridentate phosphine ligand
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A novel nitrogen-centered tridentate ligand was identified from a series of multidentate ligands and applied for the direct hydrogenation of 9 biogenic acids into alcohols, lactones and esters with high yields. Comparison of substrates and ruthenium precursors suggested that the RuII hydride cationic species was more active to transform acids than the corresponding lactone or esters.
- Deng, Li,Kang, Bin,Englert, Ulli,Klankermayer, Jürgen,Palkovits, Regina
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p. 177 - 180
(2016/02/05)
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- Synthesis of Lactones via C-H Functionalization of Nonactivated C(sp3)-H Bonds
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An electron-deficient amide is utilized as a directing group to functionalize nonactivated C(sp3)-H bonds through radical 1,5-hydrogen abstraction. The γ-bromoamides formed are subsequently converted to γ-lactones under mild conditions. The method described is not limited to tertiary and secondary positions but also allows functionalization of primary nonactivated sp3-hybridized positions in a one-pot sequence. In addition, the broad functional group tolerance renders this method suitable for the late-stage introduction of γ-lactones into complex carbon frameworks.
- Richers, Johannes,Heilmann, Michael,Drees, Markus,Tiefenbacher, Konrad
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p. 6472 - 6475
(2016/12/23)
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- A sustainable process for the production of 2-methyl-1,4-butanediol by hydrogenation of biomass-derived itaconic acid
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Pd-ReOx/C catalysts with different Re contents were prepared and employed to catalyze the aqueous hydrogenation of itaconic acid in this study. The Pd-ReOx/C catalysts were characterized by XRD, TEM, BET, NH3-TPD and H2-TPR. Results showed that the addition of ReOx species in supported Pd catalysts promoted the direct conversion of itaconic acid to 2-methyl-1,4-butanediol. The promoting effect was ascribed to the interaction between Pd and ReOx species, as has been proved by the characterizations. A 2-methyl-1,4-butanediol yield of above 80% could be obtained over Pd-3ReOx/C under the reaction condition of 180 °C, 4 MPa H2.
- Liu, Xiaoran,Wang, Xicheng,Liu, Qiang,Xu, Guoqiang,Li, Xuemin,Mu, Xindong
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- Efficient and Selective Cu/Nitroxyl-Catalyzed Methods for Aerobic Oxidative Lactonization of Diols
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Cu/nitroxyl catalysts have been identified that promote highly efficient and selective aerobic oxidative lactonization of diols under mild reaction conditions using ambient air as the oxidant. The chemo- and regioselectivity of the reaction may be tuned by changing the identity of the nitroxyl cocatalyst. A Cu/ABNO catalyst system (ABNO = 9-azabicyclo[3.3.1]nonan-N-oxyl) shows excellent reactivity with symmetrical diols and hindered unsymmetrical diols, whereas a Cu/TEMPO catalyst system (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl) displays excellent chemo- and regioselectivity for the oxidation of less hindered unsymmetrical diols. These catalyst systems are compatible with all classes of alcohols (benzylic, allylic, aliphatic), mediate efficient lactonization of 1,4-, 1,5-, and some 1,6-diols, and tolerate diverse functional groups, including alkenes, heterocycles, and other heteroatom-containing groups.
- Xie, Xiaomin,Stahl, Shannon S.
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supporting information
p. 3767 - 3770
(2015/04/14)
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- METHOD FOR PRODUCING α-METHYL-γ-BUTYROLACTONE
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PROBLEM TO BE SOLVED: To provide a producing method capable of obtaining a high-purity α-methyl-γ-butyrolactone. SOLUTION: There is provided a method for producing α-methyl-γ-butyrolactone, in producing α-methyl-γ-butyrolactone represented by following formula (1), including the steps of: adding an organic base or a salt thereof into a reaction liquid; and distilling the reaction liquid. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0043 -0044
(2017/01/02)
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- Aqueous-phase hydrogenation of biomass-derived itaconic acid to methyl-γ-butyrolactone over Pd/C catalysts: Effect of pretreatments of active carbon
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The effect of active carbon pretreatment on the catalytic performance of Pd/C catalysts in the hydrogenation of itaconic acid was studied. The catalysts were prepared by deposition-precipitation and characterized by XRD, BET, NH3-TPD, TEM and F
- Li, Sha,Wang, Xicheng,Liu, Xiaoran,Xu, Guoqiang,Han, Sheng,Mu, Xindong
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- Pichia stipitis OYE 2.6 variants with improved catalytic efficiencies from site-saturation mutagenesis libraries
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An earlier directed evolution project using alkene reductase OYE 2.6 from Pichia stipitis yielded 13 active site variants with improved properties toward three homologous Baylis-Hillman adducts. Here, we probed the generality of these improvements by testing the wild-type and all 13 variants against a panel of 16 structurally-diverse electron-deficient alkenes. Several substrates were sterically demanding, and as hoped, creating additional active site volume yielded better conversions for these alkenes. The most impressive improvement was found for 2-butylidenecyclohexanone. The wild-type provided less than 20% conversion after 24 h; a triple mutant afforded more than 60% conversion in the same time period. Moreover, even wild-type OYE 2.6 can reduce cyclohexenones with very bulky 4-substituents efficiently.
- Patterson-Orazem, Athéna,Sullivan, Bradford,Stewart, Jon D.
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p. 5628 - 5632
(2015/01/09)
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- Dehydrogenative lactonization of diols in aqueous media catalyzed by a water-soluble iridium complex bearing a functional bipyridine ligand
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A new catalytic system for the dehydrogenative lactonization of a variety of benzylic and aliphatic diols in aqueous media was developed. By using a water-soluble, dicationic iridium catalyst bearing 6,6′-dihydroxy-2, 2′-bipyridine as a functional ligand, highly atom economical and environmentally benign synthesis of various lactones was achieved in good to excellent yields. Recovery and reuse of the catalyst were also accomplished by a simple phase separation and the recovered catalyst maintained its high activity at least until the fifth run. Copyright
- Fujita, Ken-Ichi,Ito, Wataru,Yamaguchi, Ryohei
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p. 109 - 112
(2014/01/23)
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- N,S-Dimethyldithiocarbamyl oxalates as precursors for determining kinetic parameters for oxyacyl radicals
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N,S-Dimethyldithiocarbamyl oxalates (e.g.6, 10) are novel, readily prepared precursors to alkyloxyacyl radicals 1 that are more suitable for kinetic studies than existing precursors; 10 has allowed the determination of accurate rate data for the cyclization of the butenyloxyacyl radical 5 (kc = 1.2 × 107 s-1 at 21 °C). This journal is
- Kyne, Sara H.,Schiesser, Carl H.
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supporting information
p. 12040 - 12042
(2014/12/12)
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- From olefins to alcohols: Efficient and regioselective ruthenium-catalyzed domino hydroformylation/reduction sequence
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Exploring the alternatives: Ruthenium imidazoyl phosphine complexes catalyze the domino hydroformylation/reduction of alkenes to alcohols in good yields and with good selectivities (see scheme). Linear aliphatic alcohols are synthesized under reaction conditions typically used in industrial hydroformylations. Copyright
- Fleischer, Ivana,Dyballa, Katrin Marie,Jennerjahn, Reiko,Jackstell, Ralf,Franke, Robert,Spannenberg, Anke,Beller, Matthias
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supporting information
p. 2949 - 2953
(2013/04/10)
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- Synergy between the metal nanoparticles and the support for the hydrogenation of functionalized carboxylic acids to diols on Ru/TiO2
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Ruthenium nanoparticles supported on titania are over three times more active than conventional ruthenium on carbon for the hydrogenation of lactic acid. This superior catalytic activity can be due to a combined action of small ruthenium nanoparticles and the titania support.
- Primo, Ana,Concepcion, Patricia,Corma, Avelino
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scheme or table
p. 3613 - 3615
(2011/04/25)
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- Selective and flexible transformation of biomass-derived platform chemicals by a multifunctional catalytic system
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(Figure Presented) A sustainable supply chain: The controlled transformation of the biomassderived platform compounds levulinic acid (LA) and itaconic acid (IA) into the corresponding lactones, diols, or cyclic ethers (see picture) by using a multifunctional molecular catalyst is described.
- Geilen, Frank M. A.,Engendahl, Barhel,Harwardt, Andreas,Marquardt, Wolfgang,Klankermayer, Juergen,Leitner, Walter
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body text
p. 5510 - 5514
(2010/09/16)
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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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- 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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- Branched-regioselective hydroformylation with catalytic amounts of a reversibly bound directing group
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(Chemical Equation Presented) Phosphinites do the trick and work as reversibly bound catalyst-directing groups in catalytic amounts to allow for the highly regioselective hydroformylation of homo-allylic alcohols with terminal and internal alkene functions in favor of the branched product.
- Gruenanger, Christian U.,Breit, Bernhard
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supporting information; experimental part
p. 7346 - 7349
(2009/04/07)
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- METHOD FOR PRODUCING COMPOUND HAVING ACID-LABILE GROUP
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The present invention provides a process for producing a compound having a group represented by general formula (II): (wherein R1, R2, and R3 may be the same or different, and each represent a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted aralkyl, or R1 and R2 may bind to each other to form an alicyclic hydrocarbon ring together with the adjacent carbon atoms, or R2 and R3 may bind to each other to form a alicyclic heterocyclic ring together with the adjacent O-C-C that may have a substituent), which comprises allowing a compound having a hydroxyl group to react with halogenated alkyl ether represented by general formula (I): (wherein R1, R2, and R3 are the same as those defined above, respectively and X represents a halogen atom).
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- Isomerisation of ω-hydroxyalkenes under hydroxycarbonylation conditions in palladium catalysed aqueous phase systems
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The ω-hydroxyolefins 3-buten-1-ol, 3-buten-1-methyl-1-ol and 4-penten-1-ol were subjected to hydroxycarbonylation conditions in water in the presence of PdCl2(PhCN)2 and 4-8 equiv. of water soluble tris(3-sodiumsulfonatophenyl)phosphine (TPPTS), or N-bis(N′,N′-diethyl-2-aminoethyl)-4-aminomethylphenyl-diphenylphosphine (N3P). Under conditions of high conversion, the olefins primarily undergo isomerisation through a chain walking mechanism with selectivities for aldehyde ranging from 65% to 98%, with the lower values for longer chain alcohols. The lactones formed as the minor product are almost exclusively branched, indicating that in the first step 2,1-insertion is strongly favoured over 1,2-insertion. In the N3P system also linear lactone is produced at lower conversion. Running the reaction in D2O produces multiple deuterium incorporation in all positions of the carbon chain. A mechanism is discussed.
- Ionescu, Adriana,Ruppel, Markus,Wendt, Ola F.
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p. 3806 - 3815
(2007/10/03)
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- A new 2H-azirin-3-amine as a synthon for 2-methylaspartate
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The synthesis of a novel 2,2-disubstituted 2H-azirin-3-amine 3a as a building block for racemic Asp(2Me) is described. This synthon contains an ester group in the side chain. The reaction of 3a with thiobenzoic acid and the amino acid Z-Val-OH yielded the racemic monothiodiamide 10a and the dipeptide 11 as a mixture of diastereoisomers, respectively (Scheme 2). In 11, each of the protecting groups was removed selectively (Scheme 3). First attempts toward the preparation of enantiomerically pure synthons for Asp(2Me) with a chiral auxiliary group in the side chain are described. Synthons 3b with a 1-(naphthalen-1-yl)ethyl ester group and 3c with a menthyl ester group were prepared and reacted with thiobenzoic acid to form monothiodiamides 10b and 10c (Scheme 2). However, the diastereoisomers of the synthons 3b and 3c could not be separated by chromatography.
- Brun, Kathrin A.,Heimgartner, Heinz
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p. 2951 - 2959
(2007/10/03)
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- Process for preparing alpha- and beta-methyl-gamma-butyrolactone and 3-methyltetrahydrofuran
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The present invention pertains to a novel process for preparing alpha- and beta-methyl-gamma-butyrolactones (MeGBL) and/or 3-Methyltetrahydrofuran (MeTHF) from 3-(hydroxymethyl)tetrahydrofuran (HOMeTHF), 3-formyltetrahydrofuran (FTHF) or a mixture thereof
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- Process for the preparation of α-methylene-γ-butyrolactone and α-acetoxymethyl-γ-butyrolactone
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This invention pertains to a process for making α-methylene-γ-butyrolactone by acid-catalyzed rearrangement of tetrahydro-3-furoic acid. In a further embodiment, when tetrahydro-3-furoic acid is treated with acetic anhydride and an acid catalyst, α-acetoxymethyl-γ-butyrolactone is produced in high yield. Under basic conditions, α-acetoxymethyl-γ-butyrolactone can readily formα-methylene-γ-butyrolactone by the elimination of acetic acid. These reactions provide α-methylene-γ-butyrolactone by novel routes which do not require butyrolactone or formaldehyde.
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- Process for the preparation of alkyl 1-methylcyclopropanecarboxylate
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Disclosed is a 4-step process for the preparation of alkyl esters of 1-methylcyclopropanecarboxylic acid which comprises the steps of (1) converting γ-butyrolactone to α-methyl-γ-butyrolactone; (2) converting the α-methyl-γ-butyrolactone from step (1) to an alkyl 4-halo-2-methylbutyrate; (3) producing a xylene solution of the alkyl 4-halo-2-methylbutyrate; and (4) contacting the xylene solution of an alkyl 4-halo-2-methylbutyrate from step (3) with an alkali metal alkoxide under conditions of temperature and pressure which causes vaporization of (i) an alkanol as it is formed and (ii) an alkyl 1-methylcyclopropanecarboxylate as it is formed from the alkyl 4-halo-2-methylbutyrate. Also disclosed are processes whereby the alkyl 1-methylcyclopropanecarboxylate, prepared as described above, is converted to 1-methylcyclopropylamine.
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- Solvent free permanganate oxidations
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The oxidations of organic compounds by permanganate under solvent free conditions have been studied. Thiols and primary aromatic amines undergo oxidative coupling reactions to give disulfides and diazenes, respectively, sulfides are oxidized to sulfones, primary and secondary alcohols are converted to aldehydes and ketones, 1,4-diols and cyclic ethers give lactones and arenes are oxidized to the corresponding α-ketones. The experimental procedure is simple and the products are easily isolated in good yields.
- Shaabani, Ahmad,Lee, Donald G.
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p. 5833 - 5836
(2007/10/03)
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- Lactone synthesis based on atom transfer carbonylation
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(FORMULA PRESENTED) Five-to seven-membered lactones were prepared from ω-hydroxyalkyl iodides and CO by atom transfer carbonylation without the need for transition metal catalysts. The reaction proceeds via a hybrid radical/ionic mechanism in which the intramolecular alcoholysis of an ω-hydroxyacyl iodide, arising from atom transfer carbonylation, leads to the lactone.
- Kreimerman, Sergio,Ryu, Ilhyong,Minakata, Satoshi,Komatsu, Mitsuo
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p. 389 - 391
(2007/10/03)
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- Highly Enantioselective Intermolecular Cu(I)-Catalyzed Cyclopropanation of Cyclic Enol Ethers. Asymmetric Total Synthesis of (+)-Quebrachamine
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A set of cyclic enol ethers derived from 2,3-dihydrofuran 35 and 3,4-dihydropyran 8 with a varying substitution pattern at the olefinic system were synthesized. Evans's ligand 5 with Cu(I)OTf was found to be an effective catalyst in the cyclopropanation reaction between cyclic enol ethers 14, 19, 28-31, and 33 and ethyl diazoacetate 6 to give diastereoselectivities up to exo/endo = 95:5 and enantioselectivities higher than 95% in nearly all cases. Because of the selective building of a quarternary carbon center and good yields in the formation of bicyclic structures 34c-h, the reaction was used as a key step in the asymmetric synthesis of (+)-quebrachamine 7, an indole alkaloid of the Aspidosperma family. After acid-induced ring opening of bicyclic compound 34f to lactone 40 followed by LiAlH4 reduction to the masked aldehyde 41, a reaction with tryptamine gave intermediate 42. This alcohol was efficiently converted into the indole alkaloid (+)-quebrachamine 7 in an overall yield of 37% starting from the chiral synthon 34f. Moreover it revealed the absolute configuration of the quarternary center of the cyclopropanation product 34f to be S.
- Temme, Oliver,Taj, Shabbir-Ali,Andersson, Pher G.
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p. 6007 - 6015
(2007/10/03)
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- Intramolecular nucleophilic acyl substitution reactions mediated by XTi(O-i-Pr)3 (X = Cl, O-i-Pr)/2i-PrMgBr reagent. Efficient synthesis of functionalized organotitanium compounds from unsaturated compounds
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Treatment of acetylenic or olefinic carbonates and esters with a low-valent titanium reagent diisopropoxy(η2-propene)titanium (1), readily generated by the reaction of Ti(O-i-Pr)4 or ClTi(O-i-Pr)3 with 2i-PtMgX, resulted in an intramolecular nucleophilic acyl substitution (INAS) reaction to afford organotitanium compounds having a carbonyl functional group, in good to excellent yields. Thus, the treatment of alkyl alkynyl carbonates 2 or alkyl alkenyl carbonates 4 with 1 gave organotitanium compounds having a lactone and/or ester group. Similarly, alkyl alkynoates 10 or alkynyl esters 14 of carboxylic acids reacted with 1 to give organotitanium compounds having a cyclic or acyclic ketone group, respectively. Thus, the reaction provides, after hydrolysis, five- or six-membered α-alkylidene lactones and/or α,β-unsaturated esters from 2, γ-butyrolactone derivatives from 4, five- or six-membered α-alkylidene cyclic ketones from 10, and acyclic α,β-unsaturated ketones 15 from 14. In all cases, the yields are excellent and the generation of the organotitanium compounds was confirmed by deuterolysis. The organotitaniums 6 and 11c reacted smoothly with iodine to afford 2-(iodomethyl)-4-butanolide (9) and α-[iodo(trimethylsilyl)methylidene]cyclopentanone, respectively. The organotitanium compounds obtained here also reacted with aldehydes to give the corresponding adducts, thus opening up a new access to substituted α,β-butenolides from 2, to γ-butyrolactones from 4, and to the corresponding tetrasubstituted furan from 10 and 14.
- Okamoto,Kasatkin,Zubaidha,Sato
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p. 2208 - 2216
(2007/10/03)
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- Ruthenium hydrogenation catalysts
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The invention relates to a novel ruthenium complex having the formula Ru(η3 -C6 H8 -PCy2)(PCy3)Cl, wherein Cy is cyclohexyl; its use in the preparation of RuHCl(H2)(PCy3)2 and RuH2 (H2)2 (PCy3)2 ; and the use of the complexes as catalysts in hydrogenation, imination and reductive hydrolysis processes.
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- Thermolysis Reaction of 2-Acetyl-1-Oxo-Five-, Six-, and Seven-Membered Ring
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The rates of gas-phase thermolysis reactions of 2-acetylcyclopentanone 1, 2-acetylcyclohexanone 2, N-acetylcaprolactam 3, 2-acetylbutyrolactone 4, 2-acetyl-2-methylbutyrolactone 5, and 3-acetyl-2-oxazolidinone 6 have been measured over a temperature range of 50 K.They undergo unimolecular first-order elimination reactions for which log A = 11.7, 11.7, 11.2, 11.4, 11.5, and 11.1 s-1 and Ea = 193.4, 189.5, 153.2, 201.0, 206.8, and 176.1 kJ mol-1, respectively.The effect of the ring size together with the effect of a heteroatom in the ring on the rate of thermolysis reactions for compounds 1-6 is the subject of this work.
- Al-Awadi, Nouria A.,Mathew, Tommy
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p. 843 - 848
(2007/10/02)
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- Influence of 1,4-Bis(diphenylphosphino)butane on the Hydroformylation of α,β-Unsaturated Esters Catalyzed by Zwitterionic, Cationic, and Neutral Rhodium(I) Complexes. The Asymmetric Hydroformylation od α-Methylene-γ-Butyrolactone
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An investigation was made of the effect of 1,4-bis(diphenylphosphino)butane (dppb) on the regioselectivity of the hydroformylation of α,β-unsaturated esters with synthesis gas, catalyzed by rhodium(I) complexes.Excellent regioselectivity was obtained when dppb was added as a ligand for the reaction of methyl acrylate and α-methylene-γ-butyrolactone with synthesis gas.However, it inhibits the reaction when methyl methacrylate is used as the substrate.The asymmetric hydroformylation of α-methylene-γ-butyrolactone using (+)Cl(-) as the catalyst and (R)-BINAP as the chiral ligand (6:1 ratio of (R)-BINAP/Rh) gave an aldehydic lactone, containing a quaternary chiral center, in up to 37percent ee.
- Lee, Chul Woo,Alper, Howard
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p. 499 - 503
(2007/10/02)
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- Intramolecular H-Transfer Reactions During the Decomposition of Alkylhydroperoxides in Hydrocarbons as the Solvents
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Eight defined primary and secondary alkylhydroperoxides were decomposed in n-alkanes as the solvent, mostly in the presence of manganese stearate.In all cases the corresponding alcohols and carbonyl compounds were formed as the main products with yields of 60-90percent.Besides, difunctional products were formed by an intramolecular H-transfer in the alkoxy radicals corresponding to the starting hydroperoxides.Products possibly formed by an intramolecular H-transfer in the corresponding alkylperoxy radical could be found only in the case of 4-methyl-2-hydroperoxy pentane.The amount of products formed by intramolecular H-transfer depended on the nature of the C-H bond in δ-position to the original hydroperoxy group and lay between 4percent (primary C-H in the case of 4-hydroperoxy heptane) and 13percent (tertiary C-H in the case of 2-hydroperoxy-5-methyl hexane) with respect to the starting hydroperoxide.The amount of products formed by oxidative attack of the alkoxy and alkylperoxy radicals at the normal paraffins used as the solvents was unexpectedly low (always less than 10percent with respect to the starting hydroperoxide).An increment system is proposed for the calculation of 13C-nmr shifts in alkyl hydroperoxides.
- Jinsheng, Li,Pritzkow, Wilhelm,Voerckel, Volkmar
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- Selective Mono-methylation of Arylacetonitriles and Methyl Arylacetates by Dimethyl Carbonate
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Both arylacetonitriles and methyl arylacetates react with dimethyl carbonate (DMC) (20 molar excess) at 180 - 200 deg C in the presence of K2CO3 to produce monomethylated 2-arylpropionitriles and methyl 2-arylpropionates, respectively, with a selectivity >99.5percent.The reaction, with wide application, proceeds by DMC acting as a methoxycarbonylating agent towards the ArCH-X anion (X = CN, CO2Me) and as a methylating agent to ArC-(CO2Me)X.DMC also proved to be the best solvent for such reactions.
- Selva, Maurizio,Marques, Carlos Alberto,Tundo, Pietro
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p. 1323 - 1328
(2007/10/02)
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- Synthesis of γ- and δ-Lactones by Free-Radical Annelation of Se-Phenyl Selenocarbonates
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A general method for the synthesis of γ- and δ-lactones through the intramolecular addition of alkoxycarbonyl radicals, formed by reaction of Se-phenylselenocarbonates with n-Bu3SnH, onto carbon-carbon multiple bonds is described.This free-radical cyclization is characterized by high regioselectivity favoring exo addition and by a high ratio of cyclization to reduction.Monocyclic, fused bicyclic, and spirocyclic lactones are formed in good to excellent yield.Use of allyltri-n-butyltin as a chain-transfer agent in the place of n-Bu3SnH affords the corresponding 3-butenyl lactones.
- Bachi, Mario D.,Bosch, Eric
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p. 4696 - 4705
(2007/10/02)
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- The reaction of ketene-iminium ions with various olefins: A new preparation method for grandisol, fragranol and related dimethyl ethers
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We describe here the preparation of grandisol, fragranol and several related cyclobutanic by-products by procedures employing a [2+2] cycloaddition reaction between an olefine and a ketene-iminium cation generated in situ from an α-chloroenamine. The region- and stereospecificity of these cyclization reactions are studied.
- Grandguillot,Rouessac
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p. 5133 - 5148
(2007/10/02)
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- Reactions of unsaturated amides under hydroformylation conditions
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N,N-diethyl methacrylamide (1) undergoes hydroformylation, followed by subsequent reactions, under "oxo" conditions involving use of Rh4(CO)12 or Rh4(CO)12 in the presence of (R,R)-Diop (Diop = 2,2-dimethyl-1,3-dioxolane-4,5-diylbis (methylene)bis(diphenylphosphine)) as the catalyst precursor.The product first formed arises from formylation at the unsubstituted unsaturated carbon atom, and subsequently gives α-methyl-γ-butyrolactone (1b), N,N-diethyl 2-methyl-4-hydroxy-butyramide (1e), and N, N-diethyl 1-methyl-3-(diethylamino)butyramide (1f).Hydrogenation of the substrate takes also place.The product distribution can be strongly influenced by the reactions conditions.For N,N,N',N'-tetraethyl itacondiamide (2) under similar reactions conditions only hydrogenation and isomerization products are formed.
- Kollar, Laszlo,Consiglio, Giambattista,Pino, Piero
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p. 389 - 394
(2007/10/02)
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- Cyclopropane Derivatives, 2. - Self-Acylation of α-Alkyl-γ-lactones To Give Bis(1-alkylcyclopropyl)ketones via Spiroacetals
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High-yield synthetic ways are recommended for the title lactones 1.The coupling of two 2-alkyl-4-butanolides is possible in an inter-(1b, c) or intramolecular fashion (4c) to give spiroacetals 8 or 9, respectively, in the absence of hindering substituents.Symmetrically substituted bis(1-alkylcyclopropyl)ketones 12 and 13 may be prepared by acidic cleavage of those spiroacetals lacking 2,7-substituents.
- Boehrer, Gerald,Knorr, Rudolf,Boehrer, Petra
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p. 2161 - 2166
(2007/10/02)
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- Homolytic cyclization of O-alkenyl-Se-phenylselenocarbonates. Synthesis of lactones
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O-Alk-3-enyl- and O-alk-4-enyl-Se-phenylselenocarbonates undergo regio-specific exo cyclization to the corresponding γ- and δ-lactones on treatment with tri-n-butylstannane and AIBN.
- Bachi, Mario D.,Bosch, Eric
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p. 579 - 582
(2007/10/02)
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- HIGHLY REGIOSELECTIVE RING-OPENING OF α-SUBSTITUTED CYCLIC ACID ANHYDRIDES CATALYZED BY LIPASE
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Lipase Amano P irreversibly catalyzed a ring-opening of α-substituted cyclic acid anhydrides 1 preferentially at the less hindered carbonyl group to give monoesters with high regioselectivity.
- Hiratake, Jun,Yamamoto, Kazuyoshi,Yamamoto, Yukio,Oda, Jun'ichi
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p. 1555 - 1556
(2007/10/02)
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