- Precursor of α-methylene-γ-butyrolactone involved in the insecticidal activity of thunberg spiraea, Spiraea thunbergii
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6-Tuliposide A {6-O-(4-hydroxy-α-methylenebutyryl)-D-glucopyranose} was isolated from thunberg spiraea (Spiraea thunbergii) leaves. Acid-hydrolysis of this compound generated tulipalin A (α-methylene-γ-butyrolactone). This compound is thus considered as a precursor of insecticidal tulipalin A.
- Kim, Chul-Sa,Datta, Probal Kanti,Hara, Tetsuro,Itoh, Eiji,Horiike, Michio
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Read Online
- Bicomponent transparent polyester networks with shape memory effect
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Elastic bicomponent networks with shape memory effect were obtained via cross-linking reactions of unsaturated polyester with methacrylates. Unlike conventional shape memory polymers, the new material is transparent, rubbery, and can be tailored to various transition temperatures by macromolecular engineering. Various unsaturated copolymers of α-methylene-γ- butyrolactone and ε-caprolactone were synthesized by ring-opening mechanism. Depending on the composition of the unsaturated polyester materials, their mechanical properties and glass transition temperature were varied.
- Zhou, Jiawen,Schmidt, Annette M.,Ritter, Helmut
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Read Online
- 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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- Ligand-Controlled Palladium-Catalyzed Carbonylation of Alkynols: Highly Selective Synthesis of α-Methylene-β-Lactones
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The first general and regioselective Pd-catalyzed cyclocarbonylation to give α-methylene-β-lactones is reported. Key to the success for this process is the use of a specific sterically demanding phosphine ligand based on N-arylated imidazole (L11) in the presence of Pd(MeCN)2Cl2 as pre-catalyst. A variety of easily available alkynols provide under additive-free conditions the corresponding α-methylene-β-lactones in moderate to good yields with excellent regio- and diastereoselectivity. The applicability of this novel methodology is showcased by the direct carbonylation of biologically active molecules including natural products.
- Beller, Matthias,Ge, Yao,Jackstell, Ralf,Jiao, Haijun,Liu, Jiawang,Spannenberg, Anke,Yang, Ji,Ye, Fei
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supporting information
p. 21585 - 21590
(2020/09/23)
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- Novel multi-dentate phosphines for Pd-catalyzed alkoxycarbonylation of alkynes promoted by H2O additive
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A series of novel multi (bi-/tri-/tetra-)-dentate phosphines with good robustness against water and oxygen were synthesized and fully characterized. It was found that the developed ionic tri-dentate phosphine (L2′) enabled Pd-catalyzed alkoxycarbonylation of alkynes most efficiently while H2O was used as an additive instead of acid. As for L2′, its unique steric configuration with two types of potential P-P chelation modes (P?P distance of 4.31 ? and 4.36 ? respectively) to Pd-centre rendered the corresponding Pd-catalyst high activity and good stability for alkoxycarbonylation of alkynes. The in situ FT-IR analysis also verified that the formation and stability of Pd–H active species were greatly facilitated with the presence of L2′ as well as H2O additive. In addition, as an ionic phosphine, L2′ based PdCl2(MeCN)2 system immobilized in RTIL of [Bmim]NTf2 could be recycled for 7 runs without obvious activity loss or metal leaching.
- Yang, Da,Liu, Lei,Wang, Dong-Liang,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
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p. 236 - 244
(2019/02/19)
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- MANUFACTURING METHOD OF α-METHYLENE-γ-BUTYROLACTONE
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PROBLEM TO BE SOLVED: To provide a method capable of manufacturing high purity α-methylene-γ-butyrolactone at high yield. SOLUTION: α-methylene-γ-butyrolactone is manufactured by reacting oxalate ester and alcoholate with γ-butyrolactone to synthesize α-oxalyl-γ-butyrolactone, neutralizing them by acid and then reacting an enol salt of the α-oxalyl-γ-butyrolactone, formaldehyde or a precursor generating formaldehyde and carbonate. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0047-0050
(2018/08/19)
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- Synthesis of methylene butyrolactone polymers from itaconic acid
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Herein, we report the transformation of β-monomethyl itaconate, an inexpensive and biorenewable alternative to petroleum feedstocks, to the high-value monomer α-methylene-γ,γ-dimethyl-γ-butyrolactone (Me2MBL) through a selective addition strategy. This strategy is also applied to the synthesis of α-methylene-γ-butyrolactone (MBL, tulipalin A), a monomer that can be polymerized to give materials with desirable properties (high decomposition temperature, glass transition temperature, and refractive index). Subsequent polymerization of both Me2MBL and MBL through reversible addition-fragmentation chain-transfer polymerization generates well-defined poly(Me2MBL) and poly(MBL) (PMBL). Physical characterization of poly(Me2MBL) shows good physical properties comparable with known PMBL materials.
- Trotta, Jacob T.,Jin, Mengyuan,Stawiasz, Katherine J.,Michaudel, Quentin,Chen, Wei-Liang,Fors, Brett P.
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p. 2730 - 2737
(2017/07/25)
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- Enzymatic synthesis of optically active lactones via asymmetric bioreduction using ene-reductases from the old yellow enzyme family
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In contrast to the widely studied asymmetric bioreduction of α,β-unsaturated carboxylic acid esters catalyzed by ene-reductases, the reaction applied to lactones remains unexplored. A broad set of ene-reductases was found to reduce various α-, β- and γ-substituted α,β-unsaturated butyrolactones to yield the corresponding saturated non-racemic lactones. Substitution patterns greatly influenced activities and stereoselectivities and lactone products were obtained in moderate to excellent yields; importantly, enzyme-based stereocontrol allowed access to both enantiomers in up to >99% ee. Chiral recognition of a distant γ-center led to kinetic resolution with remarkable enantioselectivities (E values up to 49). An unprecedented case of dynamic kinetic resolution was observed with 3-methyl-5-phenylfuran-2(5H)-one, whereby spontaneous racemization of the substrate furnished the product in up to 73% conversion and >99% ee and 96% de.
- Turrini, Nikolaus G.,Hall, Mélanie,Faber, Kurt
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p. 1861 - 1871
(2015/06/02)
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- Production Method of a-Methylene Lactone
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The present invention relates to a production method of α-methylene lactone which comprises the following steps: (A) a step of producing an enolate intermediate by making lactone react with alkyl formate under the presence of an alkoxide base; and (B) making the enolate intermediate react with paraformaldehyde. The production method of the present invention is capable of reducing the process time, improving yield, and minimizing the contamination of a reactor.
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Paragraph 0058; 0061; 0042
(2015/03/16)
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- 4-(Dimethylamino)pyridine as a catalyst for the lactonization of 4-hydroxy-2-methylenebutanoate esters
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The catalytic action of 4-(dimethylamino)pyridine (DMAP) in lactonizing 4-hydroxy-2-methylenebutanoate esters to 2-methylene-γ-butyrolactones is described. The use of DMAP, which functions as an excellent complement to the more traditional acid-catalyzed lactonization protocol, allows for the synthesis of 2-methylene-γ-butyrolactones containing acid-sensitive groups under essentially neutral conditions.
- Nicponski, Daniel R.
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supporting information
p. 2075 - 2077
(2014/04/03)
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- A new method using 2-chloro-4,6-dimethoxy-1,3,5-triazine for facile elimination of dimethylamino group in Eschenmoser's methylenation for synthesis of α,β-unsaturated esters
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A facile one-step method for the elimination of the dimethylamino group in Eschenmoser's methylenation has been developed using a combination of 2-chloro-4,6-dimethoxy-1,3,5-triazine and triethylamine. The chemoselective elimination of the dimethylamino group occurred in compounds possessing either a diethylamino group or an alkylsulfanyl group.
- Yamada, Kohei,Masaki, Kazumasa,Hagimoto, Yuri,Kamiya, Seina,Kunishima, Munetaka
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supporting information
p. 1758 - 1760
(2013/03/29)
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- Asymmetric total syntheses of (-)-penicipyrone and (-)-tenuipyrone via biomimetic cascade intermolecular michael addition/cycloketalization
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The first total syntheses of (-)-penicipyrone and (-)-tenuipyrone were accomplished enantioselectively in 12 steps with an 11% yield and 6 steps with a 28% yield from the known 4-((tert-butyldimethylsilyl)oxy)-cyclopent-2-enone, respectively, by developing a biomimetic bimolecular cascade cyclization featuring an intermolecular Michael addition/cyclo-(spiro-)ketalization sequence. The relative, absolute stereochemistry and carbon connectivity of penicipyrone was further confirmed by X-ray crystallographic analysis and comparison of optical rotations.
- Song, Liyan,Yao, Hongliang,Zhu, Liangyu,Tong, Rongbiao
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supporting information
p. 6 - 9
(2013/03/28)
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- PROCESS FOR THE PREPARATION OF 3-METHYLENE-γ-BUTYROLACTONE
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The invention relates to a process for the preparation of 3-methylene-γ-butyrolactone (Z), the process comprising a hydroformylation step wherein 1,4-butene-diol (X) or its ester derivative cis-1,4-diacetoxy butene (Y) is subjected to H2 gas and CO gas in the presence of a hydroformylation catalyst, thereby forming an intermediate product comprising a mixture of compounds containing an aldehyde group or a hemiacetal, and an oxidation step wherein the intermediate product or hydrolyzed derivative thereof is oxidized by an oxidation agent thereby forming Z.
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Page/Page column 4; 10
(2012/09/21)
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- Efficient synthesis of an A-B-C-tricycle fragment for a structural model of tolyporphin
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An efficient stereocontrolled synthesis of an A-B-C-tricycle fragment 7 for a structural model of tolyporphin 3 is described. All the rings were prepared from readily available starting materials. One of the two key steps is a selective ring-opening reaction of the lactone cycle in bicyclolactam-lactone 17 to cyanopyrrolidone 18, which introduces the chirality into synthetic compounds. The other key step is the combination of A ring with B-C-bicycle via a two-time Eschenmoser sulfide contraction. A-B-C-tricycle fragment 7 allows a new approach toward tolypophin compounds and other uroporphinoids.
- Hu, Bing C.,Zhou, Wei Y.,Liu, Zu L.,Cai, Chao J.,Xu, Shi C.
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scheme or table
p. 89 - 100
(2010/11/18)
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- A facile method for the preparation of α-methylene-γ-butyrolactones from tulip tissues by enzyme-mediated conversion
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We developed a facile method of enzyme-mediated conversion of 6-tuliposide to α-methylene-γ-butyrolactone (tulipalin). We used a tuliposide-converting enzyme for the conversion of 6-tuliposides extracted from tulip tissues into the corresponding tulipalins in high yields within 2 h at pH 7.0. The resulting tulipalins were selectively extracted by using several organic solvents.
- Kato, Yasuo,Yoshida, Hiroyuki,Shoji, Kazuaki,Sato, Yukio,Nakajima, Noriyuki,Ogita, Shinjiro
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scheme or table
p. 4751 - 4753
(2011/03/18)
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- Purification and characterization of a tuliposide-converting enzyme from bulbs of tulipa gesneriana
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An enzyme that catalyzes the stoichiometric conversion of 6-tuliposide into tulipalin was purified and characterized from bulbs of Tulipa gesneriana. The enzyme appeared to be a dimer, the relative molecular mass (Mr) of each subunit being 34,900; it had maximum activity and stability at neutral pH and moderate temperature. The enzyme preferentially acted on such glucose esters as 6-tuliposides, and to a lesser extent on /7-nitrophenylacetate.
- Kato, Yasuo,Shoji, Kazuaki,Ubukata, Makoto,Shigetomi, Kengo,Sato, Yukio,Nakajima, Noriyuki,Ogita, Shinjiro
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experimental part
p. 1895 - 1897
(2010/03/25)
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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 75-76, 84-85; 91; 93
(2008/06/13)
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- A convenient synthesis of olefins via deacylation reaction
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A convenient and environmentally-friendly synthetic method of olefins via deacylation reaction is described. The reaction gives olefins by condensation of aldehydes with a variety of 1,3-dicarbonyl compounds in the presence of anhydrous potassium carbonate at room temperature in high yields (70-90%) in one step. The synthetic potential of this strategy can be used as an alternative procedure to the Wittig, Wittig-Horner reactions. The stereochemistry of the resulted olefins was determined by NOE experiment with correct radio frequency and X-ray analysis. The E/Z selectivity of the deacylation reaction depends on the α-substituents of the 1,3-dicarbonyl compounds.
- Nakatsu, Shogo,Gubaidullin, Aider T.,Mamedov, Vakhid A.,Tsuboi, Sadao
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p. 2337 - 2349
(2007/10/03)
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- Synthesis of α-amino γ-butyrolactone derivatives by aziridination of α-ylidene γ-butyrolactones
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The reactions of exocyclic α,β-unsaturated γ-lactones with NsONHCO2Et and CaO produce N-(ethoxycarbonyl) spiroaziridino γ-lactones. By reaction with acetic acid these products give ring opening reaction and acetylated N-protected α-amino γ-butyrolactones are obtained. The ring opening reaction is quantitative and highly regioselective.
- Gasperi, Tecla,Loreto, M. Antonietta,Tardella, Paolo A.,Veri, Elisabetta
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p. 4953 - 4956
(2007/10/03)
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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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Page column 9-10
(2008/06/13)
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- Carbonylation of alkynols catalyzed by Pd(II)/2-PyPPh2 dissolved in organic solvents and in ionic liquids: A facile entry to α-methylene γ- and δ-lactones
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The carbonylation of terminal 3-alkyn-1-ols and 1-alkyn-4-ols by Pd(OAc)2 associated with 2-(diphenylphosphino)pyridine (2-PyPPh2) dissolved in organic solvents or in 1-n-butyl-3-methyl imidazolium ionic liquids affords quantitatively and selectively exo-α-methylene γ- and δ-lactones, respectively. In the case of the reactions performed in ionic liquids (biphasic conditions), the lactones were isolated by simple distillation and the ionic catalyst solution can be reused.
- Consorti, Crestina S,Ebeling, Gunter,Dupont, Jaírton
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p. 753 - 755
(2007/10/03)
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- Production method of α-methylene-γ-butyrolactones
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The present invention relates to a method for producing an α-methylene-γ-butyrolactone which is one of basic structures often shown in drugs such as an anti-cancer agent by reacting an alene compound having an aldehyde or ketone group with carbon monoxide via cyclization in a single step in the presence of a catalyst containing ruthenium, thereby improving total yield of the entire reaction and achieving effects of cost reduction.
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- Process for the preparation of a-methylenelactones and a-substituted hydrocarbylidene lactones
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This invention pertains to a process for making α-methylenelactones and α-substituted hydrocarbylidene lactones. More specifically, the present invention obtains high yields of α-methylene-γ-butyrolactone by heating γ-butyrolactone and diethyl oxalate in the presence of a base. The second step comprises treatment of the α-oxalyl enolate salt with formaldehyde to afford the α-methylene-γ-butyrolactone.
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- Process for the preparation of α-methylenelactones and α-substituted hydrocarbylidene lactones
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This invention pertains to a process for making α-methylenelactones and α-substituted hydrocarbylidene lactones. The present invention obtains high yields of α-methylene-γ-butyrolactone by heating γ-butyrolactone and formaldehyde in the presence of a base.
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- Synthesis of α-Alkylidene-β-ethoxycarbonyl cyclopentanones and -γ-butyrolactones
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Synthesis of (E,Z)-α-Alkylidene-β-ethoxycarbonyl cyclopentanones 5 and (E,Z)-α-alkylidene-γ-butyrolactones 7 by condensing phosphonates 3 or 6 with a variety of aldehydes in the presence of aqueous potassium carbonate (6-10M) as base is reported.
- Beji,Besbes,Amri
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p. 3947 - 3954
(2007/10/03)
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- Direct indium-promoted preparation of α-methylene-γ-lactones from 2- (bromomethyl)acrylic acid and carbonyl compounds
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The reaction of 2-(bromomethyl)acrylic acid (2) with different carbonyl compounds 1 [CH2O, (E)-CH3CH=CHCHO, (i)PrCHO, (t)BuCHO, PhCHO, CH3(CH2)5CHO, c-C6H11CHO, Ph2CHCHO, (CH2)5CO, furfural, 1,4- cyclohexanedione, 2-chlorocyclohexanone, 2-hydroxybenzaldehyde, phthaldehyde, N-Boc-3-indolecarboxaldehyde, cholestanone, (1R)-(-)-myrtenal] and indium powder in a 1:1 THF:H2O mixture at room temperature affords, after acidic work-up with 6M hydrochloric acid, the corresponding α-methylene-γ-lactones 3.
- Choudhury, Prabir K.,Foubelo, Francisco,Yus, Miguel
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p. 10779 - 10788
(2007/10/03)
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- New radical reactions of S-alkoxycarbonyl xanthates. Total synthesis of (±)-cinnamolide and (±)-methylenolactocin
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Irradiation with visible light of S-alkoxycarbonyl xanthates derived from various alcohols gives rise to alkoxycarbonyl radicals with bifurcate reactivity: loss of carbon dioxide leads to deoxygenated derivatives (i.e. alkyl xanthates) whereas intramolecular addition to a suitably located double bond produces lactones; these new reactions were applied to the total synthesis of (±)-cinnamolide and (±)-methylenolactocin.
- Forbes, Judith E.,Saicic, Radomir N.,Zard, Samir Z.
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p. 3791 - 3802
(2007/10/03)
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- Indium-promoted preparation of substituted α-methylene-γ-lactones from 2-(bromomethyl)acrylic acid and carbonyl compounds
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The reaction of 2-(bromomethyl)acrylic acid (1) with different carbonyl compounds (2) [CH20, (E)-CH3CH=CHCHO, Pr(i)CHO, Bu(t)CHO, PhCHO, CH3(CH2)5CHO, c-C6H11CHO, Ph2CHCHO, (CH2)5CO] and indium powder in a 1:1 THF:H20 mixture at room temperature affords, after acidic work-up with hydrochloric acid, the corresponding α-methylene-γ-butyrolactones 3.
- Choudhury, Prabir K.,Foubelo, Francisco,Yus, Miguel
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p. 3581 - 3584
(2007/10/03)
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- Thiophosphates and selenophosphates in organic synthesis. A new approach to exocyclic olefins and bicyclic enones
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Efficient synthesis of α-methylene-cycloalkanones, α-methylene-lactones and α-alkylidene-lactones as well as bicyclic enones were developed using thiophosphates 3, 9, 15 and selenophosphates 4 as key intermediates.
- Skowrońska, Aleksandra,Krawczyk, Ewa,Koprowski, Marek,Dybowski, Piotr
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p. 409 - 412
(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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- Process for converting α-acyl-substituted lactones to α-alkylidene-substituted lactones
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A convenient stereoselective process for the preparation of α-alkylidene-substituted-γ-butyrolactones and δ-valerolactones is provided. The process involves reacting an α-acyl lactone, an aldehyde, and an alkali metal hydroxide in an inert diluent at an elevated temperature while removing water.
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- Synthesis and reactivity of bicyclomycin C(3′) amines
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The novel bicyclomycin C(3′) tertiary amines 6-8 were prepared in which morpholine, N-acetylpiperazine, and N-carboethoxypiperazine were installed at the C(3′) site in bicyclomycin (1), respectively. Previous attempts to synthesize bicyclomycin C(3′) amines were unsuccessful. Compounds 6-8 were found to be more reactive than 1 in neutral and basic solutions. Under these conditions, a novel ring fragmentation process occurred to give a monosubstituted hydantoin (i.e., 15, 18, 19) and α-methylene-γ-butyrolactone (17). Pathways for the formation of hydantoins 15, 18, and 19 and butyrolactone 17 are proposed, and evidence is presented in support of these hypotheses. The potential significance of this ring fragmentation process in future drug design is discussed.
- Park, Hyeung-Geun,Vela, Marco A.,Kohn, Harold
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p. 471 - 478
(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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- Substituent variation in azabicyclic triazole- and tetrazole-based muscarinic receptor ligands
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The effect of variation of the 1-azabicyclic substituent on the novel 1,2,3-triazol-4-yl-, 1,2,4-triazol-1-yl-, tetrazol-5-yl-, and tetrazol-2-yl- based muscarinic receptor ligands has been studied, and the exo- azabicyclic[2.2.1]hept-3-yl substituent was found to give the most potent and efficacious compounds. In addition, variation of the second substituent on 1,2,4-triazol-1-yl- and tetrazol-2-yl-based muscarinic receptor ligands has yielded a series of novel compounds with high potencies and efficacies, ranging from full agonists to antagonists. Small lipophilic electron withdrawing substituents give potent but low efficacy compounds, while small polar electron donating substituents give potent and efficacious compounds. The activity of these compounds is described in terms of a model of the receptor involving lipophilic and hydrogen bonding interactions. These compounds provide muscarinic ligands with high potency and a range of efficacies suitable for testing as candidate drugs in the treatment of Alzheimer's disease.
- Jenkins,Wadsworth,Bromidge,Orlek,Wyman,Riley,Hawkins
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p. 2392 - 2406
(2007/10/02)
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- Conversion of Hydroxyl Groups in Alcohols to Other Functional Groups with N-Hydroxy-2-thiopyridone, and Its Application to Dialkylamines and Thiols
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The radical decarboxylation reaction of N-alkoxyoxalyloxy-2-thiopyridone which was prepared by the reaction of alcohol, oxalyl chloride, and N-hydroxy-2-thiopyridone was studied both in the absence and presence of olefinic compounds.The same reactions with olefinic and acetylenic alcohols gave the corresponding lactone derivatives.On the other hand the unsymmetrical alkyl 2-pyridyl disulfides were obtained by the same reaction with aliphatic thiols.
- Togo, Hideo,Fujii, Misa,Yokoyama, Masataka
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- Preparation of 1,1-disubstituted ethylene compounds
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1,1-disubstituted ethylene compounds of the general formula I STR1 where Z is COOR2, CN or COR3, R1 is an aliphatic, cycloalophatic, araliphatic, aromatic or heterocyclic radical which may be further substituted by functional groups which are inert under the reaction conditions, R2 is an aliphatic, cycloaliphatic or araliphatic radical of 1 to 15 carbon atoms and R3 is an aliphatic, cycloaliphatic or araliphatic radical of 1 to 15 carbon atoms which may be substituted by groups which are inert under the reaction conditions, and R1 together with R2 or R1 together with R3 may furthermore form an alkylene chain of 2 to 10 carbon atoms which may be substituted by groups which are inert under the reaction conditions, are prepared from a formyl compound of the general formula II STR2 where Z, R1, R2 and R3 have the above meanings, by a process in which the reaction is carried out in the presence of formaldehyde or paraformaldehyde and (a) a C1 -C12 -alkanol or (b) a mixture of a C1 -C12 -alkanol and water or (c) with water in the presence of a secondary amine and a protic acid at from 0° to 200° C.
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- DEHALOALKOXYCARBONYLATION REACTIONS. PART V. A NEW APPROACH TO THE SYNTHESIS OF DIHYDRO-3-METHYLENE-2(3H)-FURANONE
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A simple procedure for the preparation of tulipalin A (dihydro-3-methylene-2(3H)-furanone) based on the dehydrated-alumina catalyzed β-debromomethoxycarbonylation reaction of methyl tetrahydro-3-bromomethyl-3-oxo-3-furancarboxylate has been described.
- Bukowska, Maria,Kolodziejek, Wojciech,Prejzner, Jan
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p. 573 - 576
(2007/10/02)
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- ONE-POT PREPARATION OF γ-BUTYROLACTONE DERIVATIVES FROM OLEFINIC ALCOHOLS VIA INTRAMOLECULAR RADICAL CYCLIZATION REACTION
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γ-Butyrolactone derivatives were obtained in moderate yields to good yields via the radical decarboxylation of the mixed esters which were generated from olefinic alcohols by successive treatments with oxalyl chloride and N-hydroxy-2-thiopyridone.
- Togo, Hideo,Yokoyama, Masataka
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p. 437 - 441
(2007/10/02)
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- The Stereochemistry of Organometallic Compounds. XXX. Hydrocyanation of Alkynol Ethers: a New Stereospecific Route to α-Alkylidene γ-Lactones
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The regioselectivity of hydrocyanation of a range of protected α- and β-hydroxyalkynes has been investigated and shown to by highly susceptible to steric effects.Some of the products from hydrocyanation of protected β-hydroxyalkynes have been converted into α-alkylidene γ-lactones.
- Jackson, W. Roy,Perlmutter, Patrick,Smallridge, Andrew J.
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p. 251 - 261
(2007/10/02)
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- A General Synthetic Method for α-Methylene Compounds by the Palladium-Catalyzed Decarboxylation-Deacetoxylation of Allyl α-Acetoxymethylcarboxylates Substituted by an Electron-Withdrawing Group at α-Position
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Allyl α-acetoxymethylcarboxylates substituted by ester, amide, nitro, cyano, and sulfonyl groups at α-position undergo smooth palladium-catalyzed decarboxylation-deacetoxylation under mild neutral conditions to afford corresponding α-methylene compounds in high yields.
- Tsuji, Jiro,Nisar, Mohammad,Minami, Ichiro
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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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- FACILE SYNTHESIS OF 2-METHYLENE-4-BUTYROLACTONES
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2-Methylene-4-butyrolactones were conveniently synthesized by treatment of an aldehyde with 2-carboethoxyallyl(-ic) bromide and metallic tin (and aluminium) in good yields.Protolichesterinic acid was synthesized by employing the method.
- Nokami, Junzo,Tamaoka, Takashi,Ogawa, Hideki,Wakabayashi, Shoji
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p. 541 - 544
(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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- A New Stereospecific Route to α-Alkylidene γ-Lactones
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Hydrocyanation of a range of protected β-hydroxyalkynes gives unsaturated nitriles which can be cyclised to α-alkylidene γ-lactones and in most cases the regioselectivity of hydrocyanation can be controlled giving the desired cyanoalkenes with stereospecific formation of the E-isomer.
- Jackson, W. Roy,Perlmutter, Patrick,Smallridge, Andrew J.
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p. 1509 - 1510
(2007/10/02)
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- MECHANISM OF ACETYLENE AND OLEFIN INSERTION INTO PALLADIUM-CARBON sigma BONDS.
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The intramolecular acetylene insertion reactions of C1L//2PdCO//2(CH//2)//nC EQUVLNT CCH//3 (1a, L equals Ph//3P, n equals 2; 1b, L equals p-tol//3P, n equals 2; 2, L equals Ph//3P, n equals 3) and the intramolecular olefin insertion reaction of C1L//2PdCO//2CH//2CH//2CH equals CH//2 (3, L equals Ph//3P) have been investigated. The acetylene insertion reactions give stable vinyl complexes 5a, 5b, and 6; the olefin insertion reaction gives an unsaturated lactone by beta -hydrogen elimination from the initially formed insertion product. Kinetic and **3**1P NMR studies show that, as predicted by Thorn and Hoffmann, the reactions proceed by a four-coordinate mechanism, with the triple or double bond displacing a phosphine ligand in a rapidly maintained equilibrium prior to insertion. The triple bond in 2, with the longer carbon chain, is more easily coordinated than that in 1a but inserts less rapidly after coordination.
- Samsel,Norton
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p. 5505 - 5512
(2007/10/02)
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- A New Synthesis of α-Methylene Lactones
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The α-formylation of γ- and δ-lactones and the high yield conversion into their respective α-methylene γ- and δ-lactones are described.
- Murray, Alistair W.,Reid, Robert G.
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p. 132 - 133
(2007/10/02)
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