67116-19-2Relevant academic research and scientific papers
Carboxylative Cyclization of 2-Butenoates with Carbon Dioxide: Access to Glutaconic Anhydrides
Zhang, Ke,Zhang, Wen-Zhen,Tao, Xue-Yan,Zhang, Min,Ren, Wei-Min,Lu, Xiao-Bing
, p. 11579 - 11588 (2020/10/12)
Cyclic anhydrides are versatile synthons and functional comonomers. Herein, we reported an organic base-promoted carboxylative cyclization of 2-butenoates with carbon dioxide to produce important glutaconic anhydrides in good yields. This metal-free react
Catalytic asymmetric tamura cycloadditions
Manoni, Francesco,Connon, Stephen J.
supporting information, p. 2628 - 2632 (2014/03/21)
In the presence of a novel, tert-butyl-substituted squaramide-based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products of significant synthetic interest with excellent enantio- and diastereocontrol. The methodology is of wide scope and encompasses both homophthalic and glutaconic anhydride derivatives, which lead to structurally diverse products. Glutaconic acid-derived anhydrides undergo a clean post-cyclization decarboxylation process which is not a feature of reactions involving homophthalic acid-derived anhydrides. The unusual influence of reaction temperature on diastereocontrol has been probed, with reactions occurring at 30 °C and -30 °C delivering products epimeric at one stereocenter only, in near optical purity. Squared away: The first strategy for bringing about enantioselective Tamura reactions is reported. In the presence of a squaramide-based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products with excellent enantio- and diastereocontrol. The methodology is of wide scope and leads to structurally diverse products.
A Stereospecific Synthesis of (+/-)-Abscisic Acid
Cornforth, John,Hawes, John E.,Mallaby, Richard
, p. 179 - 185 (2007/10/02)
A convenient separation of (E)- and (Z)-3-methylpent-2-enedioic acids was devised, and it was shown that with acetyl chloride or thionyl chloride the (Z)-acid yields the cyclic anhydride while the (E)-acid forms 6-chloro-4-methylpyran-2-one.The chloropyranone by conventional chemistry gave 4-methyl-6-(2'-oxopropyl)pyran-2-one which condensed with 4-methylpent-3-en-2-one in the presence of pyrrolidine, yielding 4-methyl-6-(2',6',6'-trimethyl-4'-oxocyclohex-2'-enyl)pyran-2-one.Oxidation with selenium dioxide or t-butyl chromate then gave 6-(1'-hydroxy-2',6',6'-trimethyl-4'-oxocyclohex-2'-enyl)-4-methylpyran-2-one, which on reduction by lithium aluminium hydride and reoxidation afforded (+/-)-abscisic acid stereospecifically.
Facile synthesis of anhydromevalonolactone from ethyl acetoacetate
Nangia,Rao,Prasuna
, p. 593 - 602 (2007/10/02)
Ethyl acetoacetate was transformed to 3-methylglutaconic anhydride, which upon LAH reduction and Jones oxidation afforded anhydromevalonolactone.
Biosynthetic Studies on Tajixanthone and Shamixanthone, Polyketide Hemiterpenoid Metabolites of Aspergillus variecolor
Ahmed, Salman A.,Bardshiri, Esfandiar,McIntyre, C. Rupert,Simpson, Thomas J.
, p. 249 - 274 (2007/10/02)
The biosynthesis of tajixanthone and related metabolites of Aspergillus variecolor has been studied by incorporation experiments with simple and advanced precursors labelled with the stable isotopes 13C, 2H and 18O.Tajixanthone is shown to be derived through ring cleavage of an octaketide-derived anthraquinone with introduction of two dimethylallyl moieties.From the results of isotopic labelling experiments and chemical studies on model compounds, an overall biosynthetic pathway is proposed and information on the mechanisms of interconversion of proposed intermediates is obtained.
SYNTHESIS OF SUBSTITUTED BENZENOIDS AND BIPHENYLS VIA DIELS-ALDER CYCLOADDITION OF 6-METHOXY-2-PYRONES
Ahmed, Salman A.,Bardshiri, Esfandiar,Simpson, Thomas J.
, p. 1595 - 1596 (2007/10/02)
A convenient synthesis of substituted 6-methoxy-2-pyrones from alkyl and aryl esters is described.These pyrones undergo Diels-Alder reactions with acetylenic dienophiles to provide an efficient route to polysubstituted benzoates, phthalates and biphenyls.
A Convenient Synthesis of Isotopically Labelled Anthraquinones, Chrysophanol, Islandicin, and Emodin. Incorporation of Chrysophanol into Tajixanthone in Aspergillus variecolor
Ahmed, Salman A.,Bardshiri, Esfandiar,Simpson, Thomas J.
, p. 883 - 884 (2007/10/02)
Cycloaddition reactions of labelled 6-methoxy-3-methyl-2-pyrone (1) with naphthoquinones provide the common fungal anthraquinones, chrysophanol (2), islandicin (3), and emodin (4) suitably labelled for biosynthetic studies, as demonstrated by synthesis and incorporation of chrysophanol into the xanthone metabolite, tajixanthone (17) in Aspergillus variecolor.
Reinvestigation of a Synthesis of (R,S)-Mevalonolactone
Lewer, Paul,MacMillan, Jake
, p. 1417 - 1420 (2007/10/02)
An n.m.r. study of the reaction of 3-hydroxy-3-methylpentane-1,5-dioic acid (5) with excess of acetic anhydride is described.It has shown that 3-hydroxy-3-methylpentane-1,5-dioic acid anhydride (2), previously described by Scott and Shishido as an intermediate in their synthesis of mevalonolactone, is formed only transiently, along with 3-acetoxy-3-methylpentane-1,5-dioic acid (6).Both intermediates eventually give 3-acetoxy-3-methylpentane-1,5-dioic acid anhydride (3).To obtain (R,S)-mevalonolactone, sodium borohydride reduction of 3-hydroxy-3-methylpentane-1,5-dioic acid anhydride (2), prepared from the diacid (5) and N,N-dicyclohexylcarbodi-imide, is shown to be better than reduction of 3-acetoxy-3-methylpentane-1,5-dioic acid anhydride (3).
