- Electrochemical oxidative bromolactonization of unsaturated carboxylic acids with sodium bromide: Synthesis of bromomethylated γ-lactones
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Electrochemical oxidative bromination and cyclization sequences of unsaturated carboxylic acids were developed in this study. This approach is environmentally-friendly, using bromide anion as bromine radical precursor without external oxidizing reagents.
- Kim, Rabin,Ha, Jeauk,Woo, Jiwon,Kim, Dae Young
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supporting information
(2021/12/17)
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- A facile synthesis of γ-butenolides via cyclization of 3-alkenoic acids with dimethyl sulfoxide and oxalyl bromide
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The combination of dimethyl sulfoxide and oxalyl bromide was used to accomplish the cyclization of 3-alkenoic acids with the aid of a base to afford γ-butenolides, in which bromodimethylsulfonium salt generated in situ was proposed to serve as a Br+ source.
- Ding, Rui,Liu, Yongguo,Liu, Lei,Li, Huimin,Tao, Sichen,Sun, Baoguo,Tian, Hongyu
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supporting information
p. 3001 - 3007
(2019/08/26)
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- Comparative studies of palladium and copper-catalysed γ-arylation of silyloxy furans with diaryliodonium salts
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The γ-arylation of substituted silyl-activated butenolides has been studied using a broad scope of unsymmetrical hypervalent diaryliodonium salts via a palladium- or copper-catalysed coupling reaction, yielding interesting reactivity trends. The mild catalytic conditions and coupling partner variability provide access to synthetically useful building blocks toward the pursuit of aryl-lactone containing natural products and allows for facile diversification.
- Alexander, Taylor S.,Clay, Travis J.,Maldonado, Bryan,Nguyen, Johny M.,Martin, David B.C.
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p. 2229 - 2238
(2019/03/06)
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- Guiding a divergent reaction by photochemical control: Bichromatic selective access to levulinates and butenolides
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Allylic and acrylic substrates may be efficiently transformed by a sequential bichromatic photochemical process into derivatives of levulinates or butenolides with high selectivity when phenanthrene is used as a regulator. Thus, UV-A photoinduced cross-metathesis (CM) couples the acrylic and allylic counterparts and subsequent UV-C irradiation initiates E-Z isomerization of the carbon-carbon double bond, followed by one of two competing processes; namely, cyclization by transesterification or a 1,5-H shift and tautomerization. Quantum chemical calculations demonstrate that intermediates are strongly blue-shifted for the cyclization while red-shifted for the 1,5-H shift reaction. Hence, delaying the double bond migration by employing UV-C absorbing phenanthrene, results in a selective novel divergent all-photochemical pathway for the synthesis of fundamental structural motifs of ubiquitous natural products.
- Sutar, Revannath L.,Sen, Saumik,Eivgi, Or,Segalovich, Gal,Schapiro, Igor,Reany, Ofer,Lemcoff, N. Gabriel
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p. 1368 - 1374
(2018/02/09)
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- Activation of the hypervalent fluoroiodane reagent by hydrogen bonding to hexafluoroisopropanol
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Hexafluoroisopropan-2-ol (HFIP) is an excellent solvent for promoting fluorinations with the hypervalent fluoroiodane reagent 1 and crucially, it removes the need for transition metals or TREAT-HF activators. The fluoroiodane reagent 1 was used in HFIP to monofluorinate 1,3-ketoesters and to fluorocyclise unsaturated carboxylic acids in excellent yields under mild reaction conditions.
- Minhas, Harsimran K.,Riley, William,Stuart, Alison M.,Urbonaite, Martyna
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supporting information
p. 7170 - 7173
(2018/10/24)
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- Palladium-catalyzed asymmetric intermolecular Mizoroki-Heck reaction for construction of a chiral quaternary carbon center
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Palladium-catalyzed asymmetric intermolecular Mizoroki-Heck reaction for the construction of a chiral quaternary carbon center is developed, affording 2,2-disubstituted 2,5-dihydrofurans in high yield with excellent enantioselectivity. The products are ea
- Zhang, Qing-Song,Wan, Shi-Li,Chen, Di,Ding, Chang-Hua,Hou, Xue-Long
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supporting information
p. 12235 - 12238
(2015/07/27)
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- Convenient synthesis of α,β-unsaturated γ-butyrolactones and γ-butyrolactams via decarboxylative iodination of paraconic acids and β-carboxyl-γ-butyrolactams using 1,3-diiodo-5,5-dimethylhydantoin
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A convenient synthetic approach to α,β-unsaturated γ-butyrolactones and α,β-unsaturated γ-butyrolactams is developed. The reaction proceeds via decarboxylative iodination of paraconic acids and β-carboxyl-γ-butyrolactams, employing 1,3-diiodo-5,5-dimethylhydantoin (DIH) under irradiation, followed by dehydroiodination of β-iodo-γ-butyrolactones and γ-butyrolactams providing good yields of α,β-unsaturated γ-butyrolactones and γ-butyrolactams, which are synthetically useful building blocks in organic synthesis.
- Phae-Nok, Supasorn,Kuhakarn, Chutima,Pohmakotr, Manat,Reutrakul, Vichai,Soorukram, Darunee
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p. 11087 - 11095
(2015/11/25)
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- Indole-Catalyzed Bromolactonization in Lipophilic Solvent: A Solid-Liquid Phase Transfer Approach
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We have developed a novel indole-catalyzed bromolactonization of olefinic acids. The reaction could be conducted in lipophilic solvent through a solid-liquid phase transfer mechanism. This catalytic protocol has been applied to the synthesis of base-sensitive bromolactones. (Chemical Equation Presented).
- Chen, Tao,Foo, Thomas Jian Yao,Yeung, Ying-Yeung
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p. 4751 - 4755
(2015/08/18)
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- Copper-catalyzed aerobic C-C bond cleavage of lactols with N-hydroxy phthalimide for synthesis of lactones
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The transformation of cyclic hemiacetals (lactols) into lactones has been achieved by Cu-catalyzed aerobic C-C bond cleavage in the presence of N-hydroxy phthalimide (NHPI). The present process is composed of a multistep sequence including a) formation of exo-cyclic enol ethers by dehydration; b) addition of phthalimide N-oxyl radical to the enol ethers followed by trapping of the resulting C-radicals with molecular oxygen to form peroxy radicals; c) reductive generation of oxy radicals and subsequent β-radical fragmentation to generate lactones.
- Tnay, Ya Lin,Chiba, Shunsuke
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supporting information
p. 873 - 877
(2015/04/14)
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- Synthesis of chiral butenolides using amino-thiocarbamate-catalyzed asymmetric bromolactonization
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The asymmetric cyclization of 4,4-disubstituted 3-butenoic acids is studied. Amino-thiocarbamates are used as the catalysts and N-bromosuccinimide is used as the stoichiometric halogen source. The resulting γ-butanolide products are readily converted into the corresponding γ-butenolides (up to 58% ee) derivatives in one-pot.
- Tan, Chong Kiat,Er, Jun Cheng,Yeung, Ying-Yeung
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p. 1243 - 1246
(2014/02/14)
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- Lewis base-catalyzed electrophilic lactonization of selenyl bromide resin and facile solid-phase synthesis of furan-2(5H)-one derivatives
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A facile solid-phase synthesis approach was developed for the rapid synthesis of multi-substituted furan-2(5H)-one derivatives libraries. The synthetic strategy included the selenyl bromide resin-induced electrophilic lactonization catalyzed by Lewis base, lithiation, nucleophilic substitution and oxidation-elimination of the selenium resins. The advantages of the new method are good yields, high purity, straightforward operations and high diversity of the products, lack of odor, and good stability of the selenium resins. Copyright
- Jun He, Rong,Chun Zhu, Bing,Wang, Yu Guang
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p. 523 - 528
(2014/07/07)
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- Chiral silver phosphate-catalyzed cycloisomeric kinetic resolution of α-allenic alcohols
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A kinetic resolution of α-allenic alcohols is realized through chiral silver phosphate-catalyzed cycloisomerization with high stereoselectivity (selectivity factor up to 189) and tolerance of a variety of functional groups. A mechanistic model is proposed to interpret the origin of the high stereoselectivity and broad substrate scope.
- Wang, Yan,Zheng, Kuan,Hong, Ran
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p. 4096 - 4099
(2012/04/10)
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- Synthesis of 5,5-disubstituted butenolides based on a Pd-catalyzed γ-arylation strategy
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Methods for the construction of quaternary carbon centers are of great interest to synthetic chemists due to their presence in natural products. Development of the Pd-catalyzed arylation of butenolides with high selectivity for the γ-position allows for a
- Hyde, Alan M.,Buchwald, Stephen L.
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scheme or table
p. 2663 - 2666
(2009/10/02)
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- Catalytic addition-elimination reactions towards butenolides
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A wide range of selenium-containing reagents are known to undergo addition - elimination reactions under different reaction conditions. We report on selenium electrophiles, which are regenerated under the reaction conditions employed, and therefore only catalytic amounts of these reagents are necessary.
- Brown, Danielle M.,Niyomura, Osamu,Wirth, Thomas
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experimental part
p. 1026 - 1035
(2009/04/06)
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- Synthesis of α,β-unsaturated γ-lactones via photooxygenation of 2,3-dihydrofurans followed by ferrous ion-catalyzed gem-dehydration
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Several alkyl and aryl substituted 2,3-dihydrofurans 1a-1e were synthesized and their reactions with singlet oxygen were investigated. Photooxygenation of 1a-1e in carbon tetrachloride at ambient temperature exclusively yields allylic hydroperoxides 4a-4e. Treatment of these hydroperoxides with aqueous ferrous sulfate solution affords the corresponding α,β-unsaturated γ-lactones 6a-6e with high yields. This work provides an efficient route to the preparation of butenolide moiety, an important functionality in the structures of many natural products that exhibit biological properties.
- Chen, Yu-Zhe,Wu, Li-Zhu,Peng, Ming-Li,Zhang, Dong,Zhang, Li-Ping,Tung, Chen-Ho
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p. 10688 - 10693
(2007/10/03)
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- Synthesis of conjugated γ- and δ-lactones from aldehydes and ketones via a vinylation(allylation)-ring closing metathesis-oxidation sequence
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Nucleophilic C-vinylation and C-allylation of aldehydes and ketones followed by O-allylation of the obtained carbinols gave the corresponding allyl or homoallyl ethers, respectively. Ring-closing metathesis of these compounds afforded in many cases cyclic ethers (dihydrofurans and dihydropyrans, respectively) bearing disubstituted and trisubstituted C=C bonds. These were then subjected to allylic oxidation to yield conjugated γ- and δ-lactones. Reasons for the observed failures are presented and discussed.
- Marco, J. Alberto,Carda, Miguel,Rodríguez, Santiago,Castillo, Encarnación,Kneeteman, María N.
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p. 4085 - 4101
(2007/10/03)
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- Enantiodivergent syntheses of γ-substituted butenolides with tertiary and quaternary asymmetric centers
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Continuous nucleophilic addition with several organometallic reagents to tricyclic lactone (-)-1 proceeded diastereoselectively. Newly generated tertiary and quaternary asymmetric centers were controlled by the order in which the nucleophilic reagents were added. Using this methodology, enantiodivergent syntheses of several γ-substituted butenolides with tertiary and quaternary asymmetric centers were established from a single chiral material.
- Suzuki, Katsufumi,Inomata, Kohei
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p. 745 - 749
(2007/10/03)
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- A convergent asymmetric synthesis of γ-butenolides
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Addition of aldehydes to the new enantiomerically pure lithiated sulfoxide 4 yielded γ-butenolides of high enantiomeric purities after elimination of phenylsulfinic acid. The reaction with ketones was less stereoselective.
- Renard, Marc,Ghosez, Leon
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p. 6237 - 6240
(2007/10/03)
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- Synthesis of conjugated γ- and δ-lactones from aldehydes and ketones via a vinylation/allylation-ring closing metathesis-oxidation sequence
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Nucleophilic C-vinylation or C-allylation of aldehydes and ketones followed by O-allylation of the obtained carbinols gave the corresponding allyl ethers. Ring-closing metathesis of the latter afforded cyclic ethers (dihydrofurans and dihydropyrans, respectively) which were then subjected to allylic oxidation to yield conjugated γ- and δ-lactones.
- Carda, Miguel,Castillo, Encarnación,Rodríguez, Santiago,Uriel, Santiago,Marco, J. Alberto
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p. 1639 - 1641
(2007/10/03)
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- Lithiated 3-Tosylpropanal and 4-Tosyl-2-butanone Dimethyl Acetals as β-Acylvinyl Anion Equivalents for the Synthesis of Unsaturated 1,4-Dicarbonyl Compound and α,β-Butenolides
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The lithiation of 1,1-dimethoxy-3-tosyllpropane (7a) and 2,2-dimethoxy-4-tosylbutane (7b) followed by reaction with acyl chlorides affords, after p-toluenesulfinic acid elimination, ene-1,4-dicarbonyl compounds in a stereoselective manner.In the case of compound 7a, derived from acrolein, sequential monolithiation and reaction with carbonyl compounds give cyclic acetals, which after oxidation and elimination of p-toluenesulfinic acid are transformed into α,β-butenolides.
- Bonete, Pedro,Najera, Carmen
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p. 2763 - 2776
(2007/10/02)
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- Lactonization of Unsaturated Alcohols Catalyzed by Palladium Complexes under Neutral Conditions
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Secondary and tertiary allylic alcohols react with carbon monoxide in the presence of catalytic quantities of bis(dibenzylideneacetone)palladium (0) and 1,4-bis(diphenylphosphino)butane affording lactones in 45-92percent isolated yields. α,β-Unsaturated acids are formed by isomerization and carbonylation of primary allylic alcohols. 2-(5H)-Furanones were isolated in yields of 60-80percent when alkynols were employed as substrates for the cyclocarbonylation process.
- El Ali, Bassam,Alper, Howard
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p. 5357 - 5360
(2007/10/02)
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- A NEW METHOD FOR THE PREPARATION OF 3,5-DISUBSTITUTED BUTENOLIDES
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A convenient method for the transformation of suitably protected propargyl alcohols into 3,5-disubstituted butenolides has been developed.This organozirconium-based method transforms optically active propargyl alcohols into corresponding butenolides with no loss of optical activity.
- Buchwald, Stephen L.,Fang, Qun,King, Susan M.
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p. 3445 - 3448
(2007/10/02)
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- METHYL 3-PHENYLSULPHONYL ORTHOPROPIONATE: AN EFFICIENT REAGENT FOR THE SYNTHESIS OF γ-LACTONES AND BUTENOLIDES
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Treatment of methyl 3-phenylsulphonyl orthopropionate with n-BuLi gives the corresponding carbanion which reacts with aldehydes or ketones to yield β-phenylsulphonyl-γ-lactones.Base-catalysed elimination yields α,β or β,γ-butenolides.
- Carretero, Juan Carlos,Lombaert, Stephane De,Ghosez, Leon
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p. 2135 - 2138
(2007/10/02)
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- Synthesis of Both Enantiomers of Optically Pure Saturated and α,β-Unsaturated γ-Substituted γ-Lactones from Chiral Sulphoxides. X-Ray Molecular structure of (3R,4S)-4-Methyl-4-t-butyl-3-(p-tolylthio)butanolide and of (3R,4R)-4-(Cyclohex-1-enyl)-4-methyl-3
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The lithium carbanions of optically pure (+)-(R)-p-tolyl alkyl sulphoxides (5) reacted with lithium bromoacetate and gave (+)-(R)-3-(p-tolylsulphinyl)carboxylic acids (3).Their dimetallation produced a chiral homoenolate dianion equivalent (6) which added
- Albinati, Alberto,Bravo, Pierfrancesco,Ganazzoli, Fabio,Resnati, Giuseppe,Viani, Fiorenza
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p. 1405 - 1416
(2007/10/02)
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- (E)-1-Bromo-3,3-diethoxy-1-propene (Diethyl Acetal of 3-Bromoacrolein). A Versatile Synthon for the Synthesis of Furans, Butenolides, and (Z)-Allyl Alcohols
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A convenient preparation of the title compound allowed a study in which the α-lithio-α-bromovinyl acetal 2 could be evaluated as a precursor to furans, butenolides, and (Z)-allyl alcohols.Reaction of the lithio derivative with aldehydes, ketones, and alkyl halides took place in a convenient manner.The bromine was either transformed at a later stage to an alkyl group or reduced to hydrogen with tin hydrides.The carbonyl adducts of 2 could be transformed, on mild hydrolysis, to butenolides or 2,3-disubstituted furans.An interesting solvent system (1:1:1 THF-Et2O-pentane) allowed vinyl proton abstraction and halogen-metal exchange to take place in one pot.
- Meyers, A. I.,Spohn, Ronald F.
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p. 4872 - 4877
(2007/10/02)
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