- One-Pot γ-Lactonization of Homopropargyl Alcohols via Intramolecular Ketene Trapping
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A one-pot γ-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation/oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the γ-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot lactonization.
- Yamane, Daichi,Tanaka, Haruna,Hirata, Akihiro,Tamura, Yumiko,Takahashi, Daichi,Takahashi, Yusuke,Nagamitsu, Tohru,Ohtawa, Masaki
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supporting information
p. 2831 - 2835
(2021/05/05)
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- Cooperative iodine and photoredox catalysis for direct oxidative lactonization of carboxylic acids
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A new method for the formation of γ- and δ-lactones from carboxylic acids through direct conversion of benzylic C-H to C-O bonds is described. The reaction is conveniently induced by visible light and relies on a mild cooperative catalysis by the combination of molecular iodine and an organic dye.
- Duhamel, Thomas,Mu?iz, Kilian
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p. 933 - 936
(2019/01/23)
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- Visible-Light-Induced Aza-Pinacol Rearrangement: Ring Expansion of Alkylidenecyclopropanes
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A novel visible-light-induced aza-pinacol rearrangement was developed for the first time. In this approach, the addition of the N-centered radical to the C=C bond of alkylidenecyclopropanes delivers a variety of cyclobutanimines and γ-butyrolactones, with
- Liu, Wen-Deng,Xu, Guo-Qiang,Hu, Xiu-Qin,Xu, Peng-Fei
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p. 6288 - 6291
(2017/12/08)
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- Nucleo-Palladation-Triggering Alkene Functionalization: A Route to γ-Lactones
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An unprecedented strategy for the highly effective synthesis of γ-lactones from homoallylic alcohols was achieved by palladium catalysis in one step. The protocol affords aryl, alkyl, and spiro γ-lactones directly from readily available homoallylic alcohols in good yields with excellent functional group tolerance and high chemoselectivity under mild conditions.
- Zheng, Meifang,Chen, Pengquan,Huang, Liangbin,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 5756 - 5759
(2017/11/10)
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- Electroreductive coupling of aromatic ketones, aldehydes, and aldimines with α,β-unsaturated esters: Synthesis of 5-aryl substituted γ-butyrolactones and lactams
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The electroreductive intermolecular coupling of aromatic ketones and aldehydes with α,β-unsaturated esters in the presence of TMSCl gave the adducts as γ-trimethylsiloxy esters. The detrimethylsilylation of the adducts with TBAF afforded 5-aryl substituted γ-butyrolactones. The electroreductive coupling of N-(4-methoxyphenyl)-1-arylmethaneimines with methyl acrylate in the presence of TMSCl gave the adducts as methyl 4-aryl-4-((4-methoxyphenyl)amino)butanoates. The adducts were transformed to 5-aryl-γ-butyrolactams by cyclization with NaH and subsequent oxidation with CAN. (±)-Norcotinine was prepared from nicotinaldehyde by this method. The electroreductive coupling of aromatic ketones and aldimines with acrylonitrile in the presence of TMSCl gave 4-aryl-4-(trimethylsiloxy)butanenitriles and 4-aryl-4-((4-methoxyphenyl)amino)butanenitriles, respectively.
- Kise, Naoki,Hamada, Yusuke,Sakurai, Toshihiko
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p. 1143 - 1156
(2017/02/18)
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- Direct Synthesis of 2-Formylpyrrolidines, 2-Pyrrolidinones and 2-Dihydrofuranones via Aerobic Copper-Catalyzed Aminooxygenation and Dioxygenation of 4-Pentenylsulfonamides and 4-Pentenylalcohols
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A new method for the direct conversion of 4-pentenylsulfonamides to 2-formylpyrrolidines and a 2-ketopyrrolidine has been developed. This transformation occurs via aerobic copper-catalyzed alkene aminooxygenation where molecular oxygen serves as both oxidant and oxygen source. The 2-formylpyrrolidines can further undergo oxidative carbon-carbon bond cleavage in situ upon addition of DABCO, providing 2-pyrrolidinones. These transformations have been demonstrated for a range of 4-pentenylsulfonamides. 4-Pentenylalcohols also undergo oxidative cyclization to form γ-lactones predominantly. The reaction is chemoselective, oxidizing one alkene in the presence of others, and is compatible with several functional groups. Application of these reactions to the formal syntheses of baclofen and (+)-monomorine was demonstrated.
- Wdowik, Tomasz,Chemler, Sherry R.
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supporting information
p. 9515 - 9518
(2017/07/25)
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- MnO2-promoted carboesterification of alkenes with anhydrides: A facile approach to γ-lactones
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An efficient carboesterification of alkenes with anhydrides promoted by MnO2 has been developed to afford functionalized γ-lactones in good to excellent yields. This method shows a broad substrate scope and provides a valuable and convenient synthetic tool for constructing γ-lactones.
- Wu, Lihuan,Zhang, Zhenming,Liao, Jianhua,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 2628 - 2631
(2016/02/18)
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- Copper-Catalyzed Formal [2+2+1] Heteroannulation of Alkenes, Alkylnitriles, and Water: Method Development and Application to a Total Synthesis of (±)-Sacidumlignan D
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A copper-catalyzed three-component reaction of alkenes, alkylnitriles, and water affords γ-butyrolactones in good yields. The domino process involves an unprecedented hydroxy-cyanoalkylation of alkenes and subsequent lactonization with the creation of three chemical bonds and a quaternary carbon center. The synthetic potential of this novel [2+2+1] heteroannulation reaction was illustrated by a concise total synthesis of (±)-sacidumlignan D.
- Ha, Tu M.,Chatalova-Sazepin, Claire,Wang, Qian,Zhu, Jieping
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supporting information
p. 9249 - 9252
(2016/08/05)
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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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- Insight into the mechanism and stereochemistry of the transformations of alkyltitanium Ate-Complexes. An enhanced enantioselectivity in the cyclopropanation of the carboxylic esters with titanacyclopropane reagents
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The dependence of the stereoselectivity of the cyclopropanation reaction of g,g-diphenyl-g-butyrolactone and carboxylic esters with alkylmagnesium bromides in the presence of titanium(IV) TADDOLates on the structure of the reactants has been examined in d
- Kulinkovich, Oleg G.,Kananovich, Dzmitry G.,Lopp, Margus,Snieckus, Victor
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supporting information
p. 3615 - 3626
(2015/01/16)
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- Regioselective desymmetrization of diaryltetrahydrofurans via directed ortho-lithiation: An unexpected help from green chemistry
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An efficient functionalization of diaryltetrahydrofurans via a regioselective THF-directed ortho-lithiation is first described. This reaction can be successfully carried out in cyclopentyl methyl ether as a greener alternative to Et2O, with better results in terms of yield and selectivity and, surprisingly, also in protic eutectic mixtures competitively with protonolysis.
- Mallardo, Valentina,Rizzi, Ruggiero,Sassone, Francesca C.,Mansueto, Rosmara,Perna, Filippo M.,Salomone, Antonio,Capriati, Vito
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supporting information
p. 8655 - 8658
(2014/07/22)
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- A novel intermolecular synthesis of γ-lactones via visible-light photoredox catalysis
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Direct γ-lactone formation via visible-light photoredox catalysis has been achieved efficiently including hydroxylalkylation of aromatic alkenes and transesterification. The present photocatalytic protocol has good regioselectivity and substrate compatibility, affording a novel way to intermolecular γ-lactone synthesis by the reaction of styrenes with α-bromo esters in the absence of any external oxidants.
- Wei, Xiao-Jing,Yang, Deng-Tao,Wang, Lin,Song, Tao,Wu, Li-Zhu,Liu, Qiang
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supporting information
p. 6054 - 6057
(2014/01/06)
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- Direct lactone formation by using hypervalent iodine(III) reagents with KBr via selective C-H abstraction protocol
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We have developed a new and reliable method for the direct construction of biologically important aryl lactones and phthalides from carboxylic and benzoic acids, using a combination of hypervalent iodine(III) reagents with KBr.
- Dohi, Toshifumi,Takenaga, Naoko,Goto, Akihiro,Maruyama, Akinobu,Kita, Yasuyuki
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p. 3129 - 3132
(2008/02/09)
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- Stereoseleetive Syntheses of β,γ-Unsaturated Esters and γ-Lactones: 1-(Benzotriazol-1-yl)-3-(diphenylphosphoryl)-1-ethoxy-1-propene, a Protected =CCH2CO2Et Synthon Equivalent
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l-(Benzotriazol-l-yl)-3-(diphenylphosphoryl)-l-ethoxy-l-propene (3), prepared from N-(α-ethoxyallyl)benzotriazole (1), underwent selective Horner reactions with aldehydes to give substituted dienes. Subsequent hydrolysis of these intermediates readily produced β,γ-unsaturated esters 2a-c in good yields. Similar reactions with ketones followed by hydrolysis of 10 produced, depending on the conditions, either the corresponding γ,γ-disubstituted β,γ-unsaturated esters 11a-d or γ-lactones 9a-c and 13. A double lithiation process provided β,γ,γ-trisubstituted β,γ-unsaturated esters 15, 18, and β,γ,γ-trisubstituted γ-lactone 14.
- Katritzky, Alan R.,Feng, Daming,Lang, Hengyuan
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p. 4131 - 4136
(2007/10/03)
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- The Reaction of Arylmagnesium Halides with Succinic Anhydride
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The reaction of equimolar amounts of phenylmagnesium bromide and succinic anhydride in THF at -78 deg for 2 h gives subsequent to hydrolytic work-up, 3-benzoylpropionic acid in 76percent yield and 4,4-diphenyl-4-butyrolactone in 3percent yield.When two molar equivalents of the Grignard reagent are employed, the yields of these products are respectively 85 and 14percent.On the other hand, when four equivalents of the Grignard reagent are employed for every equivalent of succinic anhydride at 66 deg C, a diketone, 1,4-diphenylbutane-1,4-dione is obtained in 72percent yield.Other products include 4,4-diphenyl-4-butyrolactone (19percent) and 3-benzoylpropionic acid (6percent).Under comparable conditions, 4-methyl- and 4-methoxyphenylmagnesium halides react similarly with succinic anhydride, giving fair yields (49-53percent) of the corresponding diketones.However, 4-chlorophenylmagnesium chloride only gives the keto-acid (12percent) and lactone (42percent), but no diketone.
- Rahman, M. T.,Nur, H. P.
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p. 469 - 474
(2007/10/02)
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- Formation of 1,2-Dioxanes by the Use of Tris(2,4-pentanedionato)manganese(III) or Manganese(III) Acetate
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The reactions of 1,1-diphenylethene, 1,1-bis(4-chlorophenyl)ethene, 1,1-bis(4-methoxyphenyl)ethene, 1,1-bis(4-methylphenyl)ethene, 1,1-bis(4-fluorophenyl)ethene, styrene, 1-octene, cyclohexene, and cyclooctene with tris(2,4-pentanedionato)manganese(III) () in acetic acid at room temperature give 4-acetyl-3-methyl-1,2-dioxan-3-ol in 8-92percent yields, together with 3-acetyl-4-hydroxy-3-hexene-2,5-dione.The similar reactions of 1,1-diphenylethene with 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, 1-phenyl-1,3-butanedione, acetoacetanilide, and 1,3-cyclohexanedione in the presence of manganese(III) acetate also give the corresponding cyclic peroxide in good to moderate yields.The mechanisms of manganese(III)-induced 1,2-dioxane ring formation and concomitant radical side reaction are discussed.
- Nishino, Hiroshi,Tategami, Shin-ichi,Yamada, Takashi,Korp, James D.,Kurosawa, Kazu
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p. 1800 - 1809
(2007/10/02)
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- Direct Preparation of Lanthanoid Ester Homoenolates from 3-Halo Esters and Lanthanoid Metals: Their Homo-Reformatsky-Type Reaction with Carbonyl Compounds
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The direct reaction of ethyl 3-bromopropionate (2a) or 3-iodopropionate (2b) with lanthanoid metals (La, Ce, Nd, Sm) in tetrahydrofuran produces lanthanoid ester homoenolates (3), which react with ketones to give γ-lactones in good yields under mild conditions.The isolation of 3-phenylseleno (8a), 3-phenyltelluro (8b), and 3-tri-n-butylstannyl esters (10) from the reaction with diphenyl diselenide (7a), ditelluride (7b), and tri-n-butyltin iodide (9), respectively, suggests the formation of the lanthanoid ester homoenolate.
- Fukuzawa, Shin-ichi,Sumimoto, Norifumi,Fujinami, Tatsuo,Sakai, Shizuyoshi
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p. 1628 - 1631
(2007/10/02)
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- Samarium(II) Di-iodide Induced Reductive Coupling of α,β-Unsaturated Esters with Carbonyl Compounds Leading to a Facile Synthesis of γ-Lactone
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Samarium(II) di-iodide, which is a strong one-electron transfer reducing agent, is effective for the reductive coupling of α,β-unsaturated esters with carbonyl compounds, whereby substituted γ-lactones can easily be prepared in good to excellent yields under very mild conditions.Two mole equiv. of samarium(II) di-iodide to each mole equiv. of starting substrate always give reasonable yields.The presence of an alcohol is essential in the reaction, complex unidentified products being formed in the absence of an alcohol; t-butyl alcohol gave more satisfactory results than methanol and ethanol.The alcohol acts as a proton donor, the use of MeOD leading to a deuteriated γ-lactone.The reaction is applicable to both aliphatic and aromatic ketones or aldehydes, whereas the electrochemical method is limited to aliphatic substrates.The diastereoselectivity is examined in the reaction of 4-t-butylcyclo-hexanone with ethyl acrylate; an anti-isomer is produced predominantly (syn:anti = 1:9) as the result of selective axial attack.The reaction may proceed by a radical mechanism, and reaction may not involve a samarium ester homoenolate.The reaction is extended to the intramolecular reaction of an α,β-unsaturated keto ester (8-oxonon-2-enoate) leading to the ready synthesis of a bicyclic γ-lactone.
- Fukuzawa, Shin-ichi,Nakanishi, Akira,Fujinami, Tatsuo,Sakai, Shizuyoshi
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p. 1669 - 1676
(2007/10/02)
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- Lactones; XIII. Grignard Reaction Followed by Phase-Transfer Oxidation: A Convenient Synthesis of γ,γ-Disubstituted γ-Butyrolactones from γ-Butyrolactone
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Grignard reaction of γ-butyrolactones, followed by oxidation of the resulting reaction mixture produces symmetrically γ,γ-dialkylated diarylated γ-butyrolactones.Phase transfer oxidation with potassium permanganate in benzene/water proves to be the best out of twelve examined oxidation methods.The synthesis is unsuccessful with sterically hindered or oxidizable Grignard reagents.
- Lehmann, Jochen,Marquardt, Norbert
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p. 1064 - 1067
(2007/10/02)
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- A Facile and Direct Synthesis of γ-Lactones from Methyl β-Bromopropionate and Ketones mediated by Lanthanoid Metals
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ψ-Lactones were easily prepared from the direct reaction of methyl β-bromopropionate with ketones mediated by lanthanoid metals; a lanthanoid metal ester homoenolate (β-lanthanoid metal substituted ester) is postulated as a reaction intermediate.
- Fukuzawa, Shin-ichi,Fujinami, Tatsuo,Sakai, Shizuyoshi
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p. 475 - 476
(2007/10/02)
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- Reaction of Olefins with Malonic Acid Derivatives in the Presence of Manganese(III) Acetate
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The reaction of methylmalonic acid with mono- and disubstituted olefins in the presence of manganese(III) acetate yielded 2-carboxy-2-methyl-4-butanolides in moderate to good yields.The reactions of bromomalonic acid and chloromalonic acid with a variety
- Fujimoto, Noriyuki,Nishino, Hiroshi,Kurosawa, Kazu
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p. 3161 - 3168
(2007/10/02)
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- Reductive Coupling of Ketones or Aldehydes with Electron-deficient Alkenes Promoted by Samarium Di-iodide
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Samarium di-iodide is an efficient reagent for the reductive coupling of ketones or aldehydes and electron-deficient alkenes, whereby γ-lactones can be prepared in good yields from ethyl acrylate.
- Fukuzawa, Shin-ichi,Nakanishi, Akira,Fujinami, Tatsuo,Sakai, Shizuyoshi
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p. 624 - 625
(2007/10/02)
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- The Oxidation of 3,3-Diphenyl-2-propenoic Acid with Manganese(III) Acetate
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The oxidation of 3,3-diphenyl-2-propenoic acid with manganese(III) acetate in boiling acetic gave 3,3-diphenyl-2-propenyl acetate, 4-acetoxymethyl-5,5-diphenyltetrahydro-2-furanone, 3,3-diphenyl-2-propenal, 5,5-diphenyl-2,5-dihydro-2-furanone, 4-acetoxy-5,5-diphenyltetrahydro-2-furanone, benzophenone, and 2-oxo-5,5-diphenyltetrahydro-4-furancarboxylic acid.The reaction pathways are discussed.
- Kurosawa, Kazu,Tsujita, Tsuyoshi
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p. 2391 - 2394
(2007/10/02)
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- Epoxides : Part II - Synthesis of Butyrolactones
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1,1-Diarylethylene oxides (Ia-c) react with diethyl malonate in the presence of sodium ethoxide to give γ,γ-diaryl-α-ethoxycarbonyl-γ-butyrolactones (IIa-c) which yield the carboxylactones (IIIa-c) upon alkaline hydrolysis.Decarboxylation of IIIa-c furnishes the corresponding γ,γ-diaryl-γ-butyrolactones (IVa-c).
- Moussa, G. E. M.,Basyouni, M. N.,Shaban, M. E.
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p. 800 - 801
(2007/10/02)
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