Annelated furans. VI. Diels-Alder addition to 3-Methoxy-2-vinylbenzofurans

1971 ◽  
Vol 24 (9) ◽  
pp. 1883 ◽  
Author(s):  
JD Brewer ◽  
WJ Davidson ◽  
JA Elix ◽  
RA Leppik
Keyword(s):  
Maleic Anhydride ◽  
Dicarboxylic Acid ◽  
Diels Alder ◽  
Acid Anhydride ◽  
Direct Route

The Diels-Alder addition of 3-methoxy-2-vinylbenzofurans to acetylenic dienophiles has been shown to be accompanied by elimination of methanol, thus affording a direct route to polyfunctional dibenzofurans. Ethylenic dienophiles also reacted but the nature of the product varied with the dienophile: thus tetra-cyanoethylene and 2- isopropenyl-3-methoxybenzofuran (17) gave the simple 1 : 1 adduct, 1,1,2,2-tetracyano-11-methoxy-4-methyl-1,2,3,11-tetrahydrodibenzofuran (26), while addition of maleic anhydride to (17) was accompanied by elimination of methanol to form the 1,2-dihydrodibenzofuran, 4-methyl- 1,2-dihydrodibenzofuran-1,2-dicarboxylic acid anhydride (27). ��� The addition of p-benzoquinone and 1,4-naphthaquinone to (17) gave the polycyclic quinones, 6-methyl-1,4-dioxo-1,4- dihydrobenzo[b]naphtho[1,2-d]furan (28) and 7-methyl-5,13-dioxo-5,13- dihydrobenzo[b]anthra[1,2-d]furan (29) respectively. ��� The methylation of enolic 3-hydroxybenzofurans has also been studied.

The stereochemistry and regiochemistry of the Diels–Alder reactions of 6-acetoxy-2,6-dimethyl-2,4-cyclohexadienone

1981 ◽  
Vol 59 (16) ◽  
pp. 2510-2517 ◽  
Author(s):  
Hillar Auksi ◽  
Peter Yates
Keyword(s):  
Carboxylic Acid ◽  
Maleic Anhydride ◽  
Dicarboxylic Acid ◽  
Van Der Waals ◽  
Closed Shell ◽  
Diels Alder ◽  
Acid Anhydride ◽  
Propiolic Acid ◽  
High Stereoselectivity

6-Acetoxy-2,6-dimethyl-2,4-cyclohexadienone (1) and maleic anhydride in boiling benzene give a single adduct, exo-5-acetoxy-l,5-dimethyl-6-oxobicyclo[2.2.2]oct-7-ene-endo-2,3-dicarboxylic acid anhydride (2). With propiolic acid 1 gives exo-5-hydroxy-l,5-dimethyl-6-oxobicyclo[2.2.2]octa-2,7-diene-2-carboxylic acid (15). The high stereoselectivity and regioselectivity of these reactions is interpretable in terms of orbital overlap, closed-shell repulsion, steric, and van der Waals – London effects.

Reactions of phthalans with dienophiles. II. Synthesis of naphthalenes and dihydronaphthalenes by reaction of ethyl maleate and maleic anhydride with 1,1-diethoxyphthalan

1980 ◽  
Vol 58 (23) ◽  
pp. 2580-2583 ◽  
Author(s):  
Luis Contreras ◽  
David B. MacLean
Keyword(s):  
Maleic Anhydride ◽  
Dicarboxylic Acid ◽  
Atmospheric Pressure ◽  
Acid Anhydride ◽  
Diethyl Maleate ◽  
Insight Into ◽  
Mechanism Of The Reaction

The reactions of 1,1-diethoxyphthalan with diethyl maleate and with maleic anhydride have been studied. The reaction with diethyl maleate in a sealed tube gave a mixture of diethyl 1-hydroxynaphthalene-2,3-dicarboxylate and its O-ethyl derivative. The same reactants at atmospheric pressure gave the ethoxy ester above along with a mixture of isomeric diethyl 1,2-dihydro-1-hydroxy-4-ethoxynaphthalene-2,3-dicarboxylates. The reaction with maleic anhydride gave only diethyl-1-ethoxynaphthalene-2,3-dicarboxylic acid anhydride. These reactions provide further insight into the mechanism of the reaction of phthalans with dienophiles.

Isolation and identification of by-products of gas phase catalytic oxidation of anthracene to 9,10-anthraquinone

1983 ◽  
Vol 48 (1) ◽  
pp. 112-122 ◽  
Author(s):  
Ivan Chvátal ◽  
Jan Vymětal ◽  
Jaroslav Pecha ◽  
Vilím Šimánek ◽  
Ladislav Dolejš ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Catalytic Oxidation ◽  
Gas Phase ◽  
Phthalic Anhydride ◽  
Maleic Acid ◽  
Phthalic Acid ◽  
Diels Alder ◽  
Acid Anhydride ◽  
Isolation And Identification ◽  
By Products

A total of 29 associate components were identified in technical 9,10-anthraquinone. The product contained all the prominent impurities present in the starting anthracene except for 9,10-dihydroanthracene and fluorene. 9-(9'-Anthryl)-carbazole and Diels-Alder type adducts of anthracene with maleic anhydride and with maleinimide were also detected. The isolated and identified by-products of oxidation of anthracene were 1,4-anthraquinone, 4,4'-dioxo-1,1'-bianthrylidene, 4,10'-dioxo-1,9'-bianthrylidene, 1-(4'-oxy-1'-naphthylidene)-4-oxyanthracene, 2,3-naphthalenedicarboxylic acid and anhydride, and 5,7,12,14-tetrahydro-5,14;7,12-di(o-benzeno)pentacene-6,13-dione. Of the compounds formed by oxidation of the anthracene impurities, isolated and identified were dibenzo[b,d]pyrone, xanthone, 1,8-naphthalenedicarboxylic acid anhydride,9-fluorenone, and naphthol[2,3-b]thiophene-4,9-dione. As products of a deeper oxidation of the starting compounds, phthalic anhydride, maleic anhydride, maleinimide, phthalic acid, and maleic acid were found. Four additional components whose structure could not be determined were also isolated. The pathway of the anthracene oxidation is suggested.

Hetero-Diels-Alder Reactions of Enaminothione with Electrophilic Olefins. Synthesis of 2-Furyl Substituted 2H-Thiopyrans

2002 ◽  
Vol 57 (6) ◽  
pp. 637-644 ◽  
Author(s):  
Krystyna Bogdanowicz-Szwed ◽  
Artur Budzowski
Keyword(s):  
Acetic Acid ◽  
Maleic Anhydride ◽  
Acetic Anhydride ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diethyl Maleate ◽  
Diels Alder Reaction

AbstractThe hetero-Diels-Alder reaction of 1-(2-furyl)-3-(dimethylamino)-2-propene-1-thione (diene) with maleic and fumaric acids, and β-nitrostyrenes yielded 3,4-dihydro-2H-thiopyran derivatives. Treatment of some of those cycloadducts with acetic acid caused elimination of dimethylamine yielding stable 2H-thiopyrans. Reaction of the diene with maleic anhydride furnished a cycloadduct which underwent spontaneous rearrangement to form an N,N-dimethylamide derivative. Cycloadditions of the diene to maleimide, N-phenylmaleimide, diethyl maleate, fumarate and butenolide, carried out in the presence of acetic anhydride,were followed by elimination of dimethylamine, afforded stable 2H-thiopyran derivatives.

Reply to Comment on “Kinetics of a Diels−Alder Reaction of Maleic Anhydride and Isoprene in Supercritical CO2”

2003 ◽  
Vol 107 (43) ◽  
pp. 9249-9249 ◽  
Author(s):  
Evgeni M. Glebov ◽  
Larisa G. Krishtopa ◽  
Victor Stepanov ◽  
Lev N. Krasnoperov
Keyword(s):  
Maleic Anhydride ◽  
Supercritical Co2 ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Kinetics Of
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