71568-87-1Relevant academic research and scientific papers
Benzofuranone derivatives as well as preparation method and application thereof
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Paragraph 0016, (2018/01/11)
The invention discloses benzofuranone derivatives as well as a preparation method and medical application thereof, and provides the benzofuranone derivatives, the preparation method thereof and an application of pharmaceutical composition containing the d
Competition of substituents for ortho direction of metalation of veratric acid
Chau, Nguyet Trang Thanh,Nguyen, Thi Huu,Castanet, Anne-Sophie,Nguyen, Kim Phi Phung,Mortier, Jacques
, p. 10552 - 10557 (2008/12/23)
LTMP (5 equiv) metalates randomly veratric acid (1). Under external quench conditions, the thermodynamically more stable lithium 2-lithio-3,4-dimethoxybenzoate (2) reacts with a variety of electrophiles to give versatile building units that are not easily accessible by conventional means. Under in situ quench conditions (LTMP/TMSCl), a reversal of regioselectivity is observed and 6-trimethylsilyl-3,4-dimethoxybenzoic acid (10) is formed predominantly.
Synthesis of phthalideisoquinoline and protoberberine alkaloids and indolo[2,1-α]isoquinolines in a divergent route involving palladium(0)- catalyzed carbonylation
Orito, Kazuhiko,Miyazawa, Mamoru,Kanbayashi, Ryo,Tokuda, Masao,Suginome, Hiroshi
, p. 6583 - 6596 (2007/10/03)
6,7,3',4'-Alkoxy-substituted 1-(2'-bromobenzoyl)-3,4-dihydroisoquinoline methiodides 17 were treated with sodium borohydride in methanol or acetic acid to give erythro-1-(2'-bromo-α-hydroxybenzyl)-2-methyl-1,2,3,4- tetrahydroisoquinolines 19. Treatment of 17 with lithium aluminum hydride in tetrahydrofuran gave the threo-isomer 20 in preference to the erythro 19. On the basis of studies on palladium(0)-catalyzed carbonylation of 2-bromo-3,4- dimethoxybenzyl alcohol to 6,7-dimethoxyphthalide, amino alcohol 19 or 20 was treated with a catalytic amount of palladium(II) acetate and triphenylphosphine in an atmosphere of carbon monoxide in the presence of chlorotrimethylsilane and potassium carbonate in boiling toluene to give the corresponding erythro- or threo-types of phthalideisoquinoline alkaloids 1 or 2, respectively. One-pot cyclization of the erythro-amino alcohols 19 was achieved by heating in N,N-dimethylformamide containing potassium carbonate to give 2,3,8,9- or 2,3,9,10-alkoxy-substituted 5,6-dihydroindolo[2,1- α]isoquinolines 3, which have a unique tetracyclic skeleton characteristic of dibenzopyrrocoline alkaloids. Similarly, palladium-(0)-catalyzed carbonylation of 1-(2'-bromobenzyl)tetrahydroisoquinolines 21 in the presence of excess potassium carbonate was found to give 8-oxoberbines 22, which on reduction with lithium aluminum hydride can be converted to protoberberine alkaloids 4.
O-(DIHYDROBENZOFURANYL)-DIBENZO-α-PYRONES FROM UMTIZA LISTERANA
Burger, Adrian P. N.,Brandt, Edward V.,Roux, David G.
, p. 2813 - 2818 (2007/10/02)
The novel metabolites (2'S,3'R)-3,10-dihydroxy-9-O-(6'-hydroxy-2'-hydroxymethyldihydrofuran-3-yl)-dibenz--pyran-6-one and its 5',6'-dihydroxy analogue are accompanied in the heartwood of Umtiza listerana by several known flavonoids and the parent 3,9,10-trihydroxydibenz--pyran-6-one.The latter, used for structural elucidation of the complex dibenzo-α-pyrones, was synthesized via a Hurtley condensation.Key Word Index-Umtiza listerana; Leguminosae; heartwood metabolites; (2'S,3'R)-3,10-dihydroxy-9-O-(6'-hydroxy-2'-hydroxymethyldihydrobenzofuran-3-yl)-dibenz--pyran-6-one; (2'S,3'R)-3,10-dihydroxy-9-O-(5',6'-dihydroxy-2'-hydroxymethyldihydrobenzofuran-3-yl)-dibenz--pyran-6-one; 3,9,10-trihydroxydibenz--pyran-6-one; flavonoids; 1H NMR; synthesis.
