77037-46-8Relevant academic research and scientific papers
Construction of trisubstituted chromone skeletons carrying electron-withdrawing groups via PhIO-mediated dehydrogenation and its application to the synthesis of frutinone A
Li, Qiao,Zhuang, Chen,Wang, Donghua,Zhang, Wei,Jia, Rongxuan,Sun, Fengxia,Zhang, Yilin,Du, Yunfei
, p. 2958 - 2965 (2020/01/08)
The construction of the biologically interesting chromone skeleton was realized by PhIO-mediated dehydrogenation of chromanones under mild conditions. Interestingly, this method also found application in the synthesis of the naturally occurring frutinone A.
Method for synthesizing chromone derivatives through PhIO mediated dehydrogenation reaction
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Paragraph 0029-0032, (2019/12/02)
The invention discloses a method for synthesizing chromone derivatives through a PhIO mediated dehydrogenation reaction, which comprises the following steps: dissolving a benzodihydropyran-4-one derivative (II) in a solvent, and carrying out the dehydroge
Synthesis method of Frutinone compound
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Paragraph 0055; 0057, (2019/11/21)
The invention discloses a synthesis method of a Frutinone compound, which comprises the following steps: (1) under the action of Cs2CO3 and a base, substituted ethyl benzoylacetate and substituted 2-chlorobenzoyl chloride react to obtain intermediate 1; (
Controllable Rh(III)-Catalyzed Annulation between Salicylaldehydes and Diazo Compounds: Divergent Synthesis of Chromones and Benzofurans
Sun, Peng,Gao, Shang,Yang, Chi,Guo, Songjin,Lin, Aijun,Yao, Hequan
supporting information, p. 6464 - 6467 (2016/12/23)
A Rh(III)-catalyzed annulation between salicylaldehydes and diazo compounds with controllable chemoselectivity is described. AgNTf2 favored benzofurans via a tandem C-H activation/decarbonylation/annulation process, while AcOH led to chromones through a C-H activation/annulation pathway. The reaction exhibited good functional group tolerance and scalability. Moreover, only a single regioisomer of benzofuran was obtained due to the in situ decarbonylation orientation effect.
A concise total synthesis of biologically active frutinones via tributylphosphine-catalyzed tandem acyl transfer-cyclization
Yoshida, Masahito,Saito, Koya,Fujino, Yuta,Doi, Takayuki
, p. 3452 - 3458 (2014/05/06)
A concise and step-economical total synthesis of biologically active frutinones has been achieved. Tributylphosphine (PBu3) efficiently induced the tandem acyl transfer-cyclization of carbonates 5 to afford 3-methoxycarbonylflavone derivatives 4 in excellent yields. Finally, concomitant deprotection and lactonization under acidic conditions furnished the desired frutinones A (1a), B (1b), and the proposed structure of frutinone C (1c).
Flavone-3-carboxylic Acids, Esters, and Related Compounds from β-Chloroarylidenemalonates
Hormi, Osmo E. O.,Moisio, M. Riitta,Sund, B. Christian
, p. 5272 - 5274 (2007/10/02)
β-Chloroarylidenemalonates I have been transformed into β-(aryloxy)arylidenemalonates II.The ring closure of II in polyphosphoric acid leads to ethyl flavone-3-carboxylates and related compounds III.Hydrolysis of II gives β-(aryloxy)arylidenemalonic acids
Lithiation in Flavones, Chromones, Coumarins, and Benzofuran Derivatives
Costa, Ana M. B. S. R. C. S.,Dean, Francis M.,Jones, Michael A.,Varma, Rajender S.
, p. 799 - 808 (2007/10/02)
Flavones are lithiated at position 3 by lithium di-isopropylamide in tetrahydrofuran at -78 deg C and the products are stable at that temperature.Appropriate reagents replace the lithium by carboxy, ethoxycarbonyl, mercapto, methylthio, trimethylsilyl, hydroxy, and other groups, sometimes giving products not previously available.Benzofurans are preferentially lithiated at position 2 if this is free, and may not be attacked if it is blocked, but if there is an activating group (i.e., one able to co-ordinate with the lithium cation) at position 2, then lithiation occurs at position 3.In the benzofuran series ring-opening is easier and lithiation often leads directly to acetylenic phenols.Chromones can be lithiated at positions 2 and 3 depending upon the substitution pattern and whether the substituents are activating.Aurones are not easily deprotonated, and only the acetylenic phenol arising from ring opening was found in the one successful case.Coumarins tend to behave simply as esters and give amides with the lithiating reagent, but 4-methoxycoumarin is readily lithiated at position 3.It is suggested that 3-deprotonation in ethers occurs easily only when there is an ether link antiperiplanar to the proton removed, and that the lithiated species are really unstable intermediates in trans-eliminations leading to alkyne derivatives.
Synthesis of Benzopyranoisoxazol-4-ones from 2-Substituted Chromone-3-carboxylic Esters. A Reinvestigation of the Reaction of 3-Acetyl-4-hydroxycoumarins with Hydroxylamine. Synthesis of 4-(2-Hydroxybenzoyl)isoxazol-5-ones
Chantegrel, Bernard,Nadi, Abdel Ilah,Gelin, Suzanne
, p. 4419 - 4424 (2007/10/02)
A convenient method for the synthesis of ethyl 2-substituted chromone-3-carboxylates by the condensation of o-acetoxyaroyl chlorides with β-keto esters is described.These chromones are converted into the corresponding 4H-benzopyranoisoxazol-4-on
β-Deprotonation by Lithium Di-isopropylamide. Vinyl Carbanions from Oxygen Heterocycles in the Synthesis of Carboxylic Acids in the Benzofuran, Flavone, and Coumarin Series and in the Regiospecific Acylation of 2,6-Dimethylchromone
Costa, Ana M. B. S. R. C. S.,Dean, Francis M.,Jones, Michael A.,Smith, Dennis A.,Varma, Rajender S.
, p. 1224 - 1226 (2007/10/02)
Lithium di-isopropylamide at -70 deg C can remove the α-proton from benzofuran in the absence of activating groups and the β-proton if such groups are present; in flavone and 4-methoxycoumarin β-deprotonation occurs readily and the carbanions are easily carboxylated giving acids not previously accessible, while in 2,6-dimethylchromone β-deprotonation is kinetically favoured allowing 3-acylation to be achieved separately from the conventional acylation at the 2-methyl group.
