- Diastereoselective Alkene Hydroesterification Enabling the Synthesis of Chiral Fused Bicyclic Lactones
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Palladium-catalysed diastereoselective hydroesterification of alkenes assisted by the coordinative hydroxyl group in the substrate afforded a variety of chiral γ-butyrolactones bearing two stereocenters. Employing the carbonylation-lactonization products as the key intermediates, the route from the alkenes with single chiral center to chiral THF-fused bicyclic γ-lactones containing three stereocenters was developed.
- Shi, Zhanglin,Shen, Chaoren,Dong, Kaiwu
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supporting information
p. 18039 - 18042
(2021/11/16)
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- Enantioselective Synthesis of α-exo-Methylene γ-Butyrolactones via Chromium Catalysis
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Enantioenriched α-exo-methylene γ-butyrolactones have been obtained via a two-step sequence consisting of a highly enantioselective chromium-catalyzed carbonyl 2-(alkoxycarbonyl)allylation and lactonization. A variety of functional groups are compatible u
- Chen, Weiqiang,Yang, Qin,Zhou, Tian,Tian, Qingshan,Zhang, Guozhu
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supporting information
p. 5236 - 5239
(2015/11/18)
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- New antifungal scaffold derived from a natural pharmacophore: Synthesis of α-methylene-γ-butyrolactone derivatives and their antifungal activity against Colletotrichum lagenarium
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Thirty new and thirty-four known analogues were designed and synthesized to improve the potential use of the α-methylene-γ-butyrolactone ring, a natural pharmacophore. All structures were confirmed by 1H and 13C NMR, MS, and single-c
- Jun-Tao, Feng,De-Long, Wang,Yong-Ling, Wu,He, Yan,Xing, Zhang
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supporting information
p. 4393 - 4397
(2013/07/26)
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- Palladium(II)-catalyzed aerobic intermolecular cyclization of acrylic acid with alkenes to α-methylene-γ-butyrolactones
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The methodology in this article is a palladium(II)/copper(II)- or palladium(II)-catalyzed intermolecular cyclization of acrylic acid with alkenes to produce α-methylene-γ-butyrolactone derivatives using molecular oxygen as an environmentally benign oxidant. In this system, the carboxylato, especially trifluoroacetato, or trimethylacetato ligand, plays a quite important role to afford a high catalytic activity by suppressing the deposition of palladium(0) black. Copyright
- Yonehara, Koji,Miyoshi, Yasuyuki,Tsukajima, Aki,Akatsuka, Takeo,Saito, Makoto
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experimental part
p. 1071 - 1075
(2011/07/09)
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- Enantioselective addition of β-functionalized allylboronates to aldehydes and aldimines. Stereocontrolled synthesis of α-methylene-γ-lactones and lactams
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We report results regarding the development of condensations of chiral β-alkoxycarbonylallylboronates on aldehydes and imines. These allylboronates add in a highly enantioselective and diastereospecific manner to afford biologically and synthetically useful chiral α-methylene-γ-butyrolactones and lactams. The nature of the electrophile (aldehyde vs imine) is shown to have a dramatic influence on the mechanism of the reaction, probably directing the stereoselectivity of the process through different transition states.
- Chataigner, Isabelle,Zammattio, Fran?oise,Lebreton, Jacques,Villiéras, Jean
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p. 2441 - 2455
(2008/09/18)
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- METHOD FOR PRODUCING CYCLIC UNSATURATED COMPOUND
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The present invention provides a method for producing a cyclic unsaturated compound, which sufficiently suppresses generation of acyclic unsaturated compounds and permits excellent yield and reaction rate. Such a method for producing a cyclic unsaturated compound is a method for producing a cyclic unsaturated compound by reacting an a, ?-unsaturated carboxylic acid with an unsaturated organic compound, wherein the method comprises a step of reacting the a, ?-unsaturated carboxylic acid with the unsaturated organic compound in the presence of a catalyst.
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Page/Page column 83-84, 92
(2008/06/13)
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- Novel synthesis, cytotoxic evaluation, and structure-activity relationship studies of a series of α-alkylidene-γ-lactones and lactams
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5-Alkyl- and 5-arylalkyl-3-methylenedihydrofuran-2-ones 13a-e, 3-alkylidenedihydrofuran-2-ones 18a-c, and 3-methylenepyrrolidin-2-ones 16a-e were synthesized utilizing ethyl 2-diethoxyphosphoryl-4-nitroalkanoates 9a-e as common intermediates. All obtained
- Janecki, Tomasz,B?aszczyk, Edyta,Studzian, Kazimierz,Janecka, Anna,Krajewska, Urszula,Rózalski, Marek
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p. 3516 - 3521
(2007/10/03)
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- 2-Diethoxyphosphoryl-4-nitroalkanoates - Versatile intermediates in the synthesis of α-alkylidene-γ-lactones and lactams
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Michael addition of various nitroalkanes 7a-f to ethyl (2- diethoxyphosphoryl)acrylate (6) gave 2-diethoxyphosphoryl-4-nitroalkanoates 8a-f. Transformation of the nitro functionality into hydroxy or amino group and cyclization yielded 3-(diethoxyphosphory
- B?aszczyk, Edyta,Krawczyk, Henryk,Janecki, Tomasz
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p. 2685 - 2688
(2007/10/03)
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- Synthesis and biological activity of α-methylene-γ-lactones as new aroma chemicals
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Seven kinds of α-methylene-γ-lactones with an alkyl group at the C-4 position were synthesized according to a previously described method, with yields of 28-34%. These α-methylene-γ-lactones had characteristic and unique odors. All α-methylene-γ-lactones added a roast-like odor to materials. The antimicrobial effects of α-methylene-γ-lactones were investigated by using a paper disk diffusion method. The results showed the α-methylene-γ-lactones inhibited the growth of three bacteria (Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescens) and two fungi (Saccharomyces cerevisiae and Aspergillus niger). In particular, α-methylene-γ-undecalactone and α-methyleneγ-dodecalactone exhibited potent inhibition of the growth of these microorganisms compared to butyl p-hydroxybenzoate as standard antibiotic. The umu test revealed that the α-methylene-γ-lactones suppressed the SOS-inducing activity of three mutagens, furylfuramide, UV irradiation, and TrpP-1, respectively. The antimicrobial effects and the suppressive effects of SOS induction by α-methylene-γ-lactones had a tendency to intensify as the number of carbons in the side chain increased.
- Miyazawa, Mitsuo,Shimabayashi, Hiroshi,Hayashi, Shuichi,Hashimoto, Seiji,Nakamura, Sei-Ichi,Kosaka, Hiroshi,Kameoka, Hiromu
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p. 5406 - 5410
(2007/10/03)
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- A New Synthesis of γ-Substituted α-Methylene-γ-butyrolactones (2-Methylene-4-alkanolides) using Catalysis by SnCl2/Amberlyst 15
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Reaction of α-bromomethylacrylic acid with aldehydes or ketones in an SnCl2/amberlyst 15/THF/H2O system affords 2-methylene-4-alkanolides in mostly good yields.
- Talaga, Patrice,Schaeffer, Marcel,Benezra, Claude,Stampf, Jean-Luc
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- SYNTHESE VON γ-HYDROXYNITRILEN, γ-BUTYROLACTONEN UND α-METHYLENO-γ-BUTYROLACTONEN AUS EPOXIDEN UND NATRIUM-
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The highly nucleophilic ylide-anion of sodium- attacks oxiranes by ring-opening.Depending on the work-up-conditions and the further reactions being employed, γ-hydroxynitriles, γ-butyrolactones or α-methyleno-γ-butyrolactones are obtained from the primary products thus formed.
- Bestmann, Hans Juergen,Schmidt, Martin
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p. 2111 - 2114
(2007/10/02)
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- Lithiated Dimethylketene Diisopropyl Dithioacetal as a Synthon of Homoenolate Dianion of Isobutyric Ester. An Application to the Synthesis of α-Methyllactones
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Lithium anion of dimethylketene diisopropyl dithioacetal reacted with various kinds of electrophiles to afford γ-substituted products with high regioselectivity.The utility of the lithiated ketene dithioacetal, a novel homoenolate dianinon equivalent of isobutyric ester, was demonstrated in the synthesis of α-methylenelactones.
- Fujisawa, Tamotsu,Umezu, Kazuto,Suzuki, Masahiro,Sato, Toshio
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p. 1675 - 1678
(2007/10/02)
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- IMPROVED SYNTHESIS OF α-METHYLENE-γ-LACTONES VIA ORGANOTIN REAGENTS
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The products of the reaction between aldehydes and the organotin reagent (1) have been converted to the corresponding α-methylene-γ-lactones in excellent yield under extremely mild conditions.
- Baldwin, Jack E.,Adlington, Robert M.,Sweeney, Joseph B.
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p. 5423 - 5424
(2007/10/02)
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- REFORMATSKY-TYPE REACTIONS IN AQUEOUS MEDIA. USE OF BROMOMETHYLACRYLIC ACID FOR THE SYNTHESIS OF α-METHYLENE-γ-BUTYROLACTONES.
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A new method for the preparation of α-methylene-γ-butyrolactones is described.
- Mattes, Henri,Benezra, Claude
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p. 5697 - 5698
(2007/10/02)
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- SYNTHESIS OF UNSATURATED BUTYROLACTONES BY PALLADIUM CATALYZED INTRAMOLECULAR CARBOALKOXYLATION OF HOMOALLYLIC CHLOROFORMATES
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We propose a new method for the preparation of α-methylene lactones involving the palladium (0) catalyzed cyclisation of homoallylic chloroformates 1.
- Henin, Francoise,Pete, Jean-Pierre
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p. 4687 - 4690
(2007/10/02)
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- PREPARATION AND SYNTHETIC APPLICATION OF 2-BROMOALLYLTRIMETHYLSILANE AS A 1-HYDROXYMETHYLVINYL ANION EQUIVALENT
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The 1-trimethylsilylmethylvinyl group, as a 1-hydroxymethylvinyl equivalent, was readily introduced to epoxides with the corresponding Grignard reagent derived from 2-bromoallyltrimethylsilane.Obtained 2-(2-hydroxyethyl)-allylsilanes were converted to α-methylene-γ-lactones via diols.
- Nishiyama, Hisao,Yokoyama, Hiroshi,Narimatsu, Shinzo,Itoh, Kenji
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p. 1267 - 1270
(2007/10/02)
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- Palladium-Catalyzed Carbonylation of Vinyl Halides: A Route to the Synthesis of α-Methylene Lactones
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α-Methylene γ-lactones were synthesized in high yields by the palladium-catalyzed carbonylation reactions of alkyl-substituted 3-bromobut-3-en-1-ols under mild conditions.The bromo alcohols were obtained by the reaction of magnesium bromide with various epoxides followed by conversion of the trimethylsilyl group to bromide.By starting with optically active epoxides such as (R)-1,2-epoxypropane or (2R,3R)-2,3-epoxybutane, the corresponding lactones could be obtained virtually optically pure.The carbonylation reaction is selective in that it generates only γ-lactones when there is a choice of two vinylic iodides or two alcohols that could lead either to the five- or six-membered rings.
- Martin, Larry D.,Stille, J. K.
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p. 3630 - 3633
(2007/10/02)
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- Concise Syntheses of 3-Methylenetetrahydrofuran-2-one Derivatives and Related Systems
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Using the Shapiro reaction, the title compounds were prepared in 'one pot' from the consideration of two ketones, or an aldehyde and a ketone, with carbon dioxide.For example, acetone 2,4,6-tri-isopropylbenzenesulphonylhydrazone was treated in sequence with n-butyl-lithium (-50 deg C), acetone (-50 deg C), n-butyl-lithium (-78 to 0 to -78 deg C), carbon dioxide (-78 deg C), and trifluoroacetic acid (25 deg C) to give 5,5-dimethyl-3-methylenetetrahydrofuran-2-one.The reaction was extended to prepare derivatives of 3-methylenetetrahydropyran-2-one and 3,5-dimethylenetetrahydrofuran-2-one.
- Adlington, Robert M.,Barrett, Anthony G. M.
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p. 2848 - 2863
(2007/10/02)
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- Synthesis of α-Methylene-γ-butyrolactones: A Structure-Activity Relationship Study of Their Allergenic Power
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Thirty-five α-methylene-γ-butyrolactones has been prepared and their allergenic properties tested on the skin of guinea pigs experimentally sensitized to (a) alantolactone (1), (b) isoalantolactone (2), and (c) α-methylene-γ-butyrolactone (3).The two firs
- Schlewer, Gilbert,Stampf, Jean-Luc,Benezra, Claude
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p. 1031 - 1038
(2007/10/02)
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- GENERAL SYNTHESIS OF EXOMETHYLENE-γ-LACTONES VIA THE RETRO-DIELS-ALDER REACTION
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New synthetic methods of tulipalin A were deviced via the retro-Diels-Alder reaction and the generality was demostrated by the synthesis of several α-methylene-γ-alkyl-γ-butyrolactones.
- Ichihara, Akitami,Nio, Noriki,Sakamura, Sadao
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p. 4467 - 4468
(2007/10/02)
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