Annelated furans. XI. The reactions of 2-vinylfurans with acetylenic esters

1973 ◽  
Vol 26 (5) ◽  
pp. 1059 ◽  
Author(s):  
WJ Davidson ◽  
JA Elix
Keyword(s):  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Acetylenic Ester ◽  
Acetylenic Esters ◽  
Methyl Propiolate ◽  
Diene System ◽  
Alder Adduct ◽  
Ene Addition

In general dimethyl acetylenedicarboxylate and methyl propiolate have been found to react with 2-vinylfurans to give the corresponding dimethyl benzofuran-4,5-di-carboxylates and methyl benzofuran-4- carboxylates respectively. In several instances dimethyl acetylenedicarboxylate did not react exclusively with the exocyclic diene system of the 2-vinylfuran and here the corresponding dimethyl 3,6-epoxy-3-vinyl-3,6-dihydrophthalates were obtained by Diels-Alder addition to the furanoid diene system. At 80� 2-vinylfuran and dimethyl acetylenedicarboxylate formed the 1 : 2 adduct (11), the formation of which can be interpreted as involving an ene addition of a second mole of the acetylenic ester to the initially formed Diels-Alder adduct.

Reaction of 2-[(E)-styryl]Quinazolin-4(3H)-one with Acetylenic Esters: Formation of Unexpected N-3 Alkenylation Products

2005 ◽  
Vol 2005 (7) ◽  
pp. 429-431 ◽  
Author(s):  
Tapasi Chatterjee ◽  
Subhagata Chattopadhyay ◽  
Ranjan Mukhopadhyay ◽  
Basudeb Achari ◽  
Santu Chakraborty ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Alder Reaction ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Acetylenic Esters ◽  
X Ray ◽  
Methyl Propiolate ◽  
Diels Alder Reaction ◽  
Centrosymmetric Dimers

Attempted hetero Diels–Alder reaction with 2-[(E)-styryl]quinazolin-4(3H)-one (1) and dimethyl acetylenedicarboxylate (2) resulted in unexpected N-3 alkenylation products, 2-[(E)-styryl]-3-[(Z)-1,2-bis(methoxycarbonyl)vinyl]quinazolin-4(3H)-one (4a) and 3-[(E)-1,2-bis(methoxycarbonyl) vinyl] 2-[(E)-styryl]-quinazolin-4(3H)-one (4b) in low yield. Treating 1 and 2-methylquinazolin-4(3H)-one (9) with methyl propiolate (7) also furnished N-3 alkenylation products in low yield. The structure of 4b has been established by X-ray analysis. The molecules of 4b are linked by intermolecular C-H. … N hydrogen bonds into centrosymmetric dimers forming R22 (12) rings.

The Diels-Alder reaction of some styrenes and 2,2-dimethylchromenes with acetylenic esters

1969 ◽  
Vol 22 (8) ◽  
pp. 1721 ◽  
Author(s):  
JA Diment ◽  
E Ritchie ◽  
WC Taylor
Keyword(s):  
Linear Structure ◽  
Alder Reaction ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Acetylenic Esters ◽  
Methyl Propiolate ◽  
Diels Alder Reaction ◽  
Derivatives Of

Examples of the Diels-Alder reaction between some derivatives of styrene and of 2,2-dimethylchromene and dimethyl acetylenedicarboxylate and methyl propiolate, leading ultimately to fully aromatic derivatives, are described. Yields are generally low and the synthesis has limited utility. However, the n.m.r, spectrum of the product from acronycine dimethyl acetylenedicarboxylate is such as to establish the angular rather than the linear structure for acronycine.

scholarly journals Competitive Diels–Alder and ene addition of N-arylmaleimides to 7-dehydrocholesteryl acetate

1992 ◽  
Vol 70 (11) ◽  
pp. 2730-2744 ◽  
Author(s):  
William J. Leigh ◽  
Donald W. Hughes ◽  
D. Scott Mitchell
Keyword(s):  
Molecular Mechanics ◽  
Nmr Spectra ◽  
Benzene Solution ◽  
Diels Alder ◽  
Spectroscopic Techniques ◽  
Two Dimensional ◽  
A Minor ◽  
C Nmr ◽  
Alder Adduct ◽  
Ene Addition

Thermolysis of N-phenyl, N-para-biphenyl, and N-para, para′-terphenylmaleimide with 7-dehydrocholesteryl acetate in benzene solution at 200 °C yields mixtures of four cycloadducts in relative yields that are essentially independent of the maleimide substituent. The three major products are those of ene addition to C7 of the steroid with abstraction of the proton at C9 or C14. The α-endo-Diels-Alder adduct is formed as a minor product. The structures of the adducts have been elucidated on the basis of one- and two-dimensional 1H and 13C NMR spectroscopic techniques, including homonuclear 1H decoupling, NOE, 1H–1H COSY, heteronuclear 1H–13C shift correlation, and TOCSY 2-D experiments, and the results of molecular mechanics (MMX) calculations. The combination of these techniques has made it possible to almost completely assign the 1H and 13C NMR spectra for two of the ene adducts and the Diels–Alder adduct from reaction of 7-dehydrocholesteryl acetate with N-phenyl maleimide.

The reaction of steroid 2,4-dienes with acetylenes

1976 ◽  
Vol 54 (22) ◽  
pp. 3508-3516 ◽  
Author(s):  
Peter Yates ◽  
Françoise M. Walliser
Keyword(s):  
Diels Alder ◽  
The Other ◽  
Dimethyl Acetylenedicarboxylate ◽  
Methyl Propiolate ◽  
Lower Temperature

Reaction of 2,4-cholestadiene, 2,4-androstadien-17-one, or 3-trimethylsiloxy-2,4-cholestadiene with dimethyl acetylenedicarboxylate or methyl propiolate in boiling xylene results in the cleavage of rings A and B and the formation of 4-(2-arylethyl)-5-isopropenyl-7a-methyltetrahydroindane derivatives. They are considered to be formed via Diels–Alder addition of the acetylene to the steroid diene followed by a retro-Diels–Alder cleavage of the resulting bicyclo[2.2.2]octadiene system. Attempts to isolate the Diels–Alder adducts by carrying out the additions at lower temperature were unsuccessful, since no reaction occurred. However, when 2,4-androstadien-17-one was treated with dicyanoacetylene in boiling benzene, it was possible to isolate a mixture of two stereoisomeric Diels–Alder adducts containing the bicyclo[2.2.2]octadiene system in ring A; this was converted in boiling xylene to a retro-Diels–Alder product analogous to the products obtained with the other acetylenic dienophiles.

A Total Synthesis of Dimethyl 2,3-O-Isopropylidene-l-O-oxalyl-β-DL-ribo-hexofuran-5-ulosuronate

1975 ◽  
Vol 53 (18) ◽  
pp. 2701-2706 ◽  
Author(s):  
George Just ◽  
Karl Grozinger
Keyword(s):  
Total Synthesis ◽  
Title Compound ◽  
Catalytic Reduction ◽  
Major Product ◽  
Diels Alder ◽  
High Yield ◽  
Thermal Rearrangement ◽  
Dimethyl Acetylenedicarboxylate ◽  
Alder Adduct

The synthesis of the title compound 5 was accomplished by a high-yield thermal rearrangement of the ozonide (3) of dimethyl 5,6-O-isopropylidene-7-oxabicyclo[2.2.1]hept-2-ene-exo-5,6-diol-2,3-dicarboxylate (2a), which is obtained in 30% yield from the Diels–Alder adduct of furan and dimethyl acetylenedicarboxylate. Catalytic reduction of 5 gave methyl 2,3-O-iso-propylidene-β-DL-talofuranuronate (8) as the major product, accompanied by a small amount of the allo isomer 9.

Syntheses of Angucyclinones Related to Ochromycinone

1998 ◽  
Vol 51 (6) ◽  
pp. 515 ◽  
Author(s):  
Tomas Rozek ◽  
Wit Janowski ◽  
John M. Hevko ◽  
Edward R. T. Tiekink ◽  
Suresh Dua ◽  
...  
Keyword(s):  
Structural Study ◽  
Alder Reaction ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
Diels Alder Reaction ◽  
Synthetic Approaches ◽  
Alder Adduct

Two synthetic approaches have been investigated for the syntheses of model angucyclinones related to ochromycinone. The first involves a Diels–Alder/Friedel–Crafts strategy in which the Diels–Alder adduct formed between dimethyl acetylenedicarboxylate and 3-ethenyl-5,5-dimethylcyclohex-2-en-1- one was converted into 6,6-dimethyl-8-oxo-5,6,7,8-tetrahydronaphthalene-1,2-dicarboxylic anhydride, which was then reacted with benzene in a Friedel–Crafts reaction. Acid-catalysed cyclization of the Friedel–Crafts products gave 3,3-dimethyl-3,4-dihydrobenz[a]anthracene-1,7,12(2H)-trione (3) in poor yield. Angucyclinones related to (3) are formed (in 40–50% overall yield) by aromatization of the adduct formed between the appropriate 1,4-naphthoquinone and 3-[(E)-2-methoxyethenyl]- 5,5-dimethylcyclohex-2-en-1-one (this dienone reacts with itself by a Diels–Alder process to yield an adduct which decomposes to 3,3,8,8-tetramethyl-3,4,7,8-tetrahydroanthracene-1,6(2H,5H)-dione). When the substituted 1,4-naphthoquinone is unsymmetrical, a boron triacetate assisted Diels–Alder reaction gives a single regioisomer (e.g. X-ray investigations indicate that 8-hydroxy-3,3-dimethyl-3,4-dihydrobenz[a]anthracene-1,7,12(2H)-trione is the product from 5-hydroxy-1,4-naphthoquinone). An X-ray structural study of the Diels–Alder adduct in the above reaction confirms the operation of an endo cyclization.

Diels-Alder Reactions of Vinyl Derivatives of [1]Benzothieno[3,2-b]furan

1999 ◽  
Vol 64 (2) ◽  
pp. 389-407 ◽  
Author(s):  
Pavel Pihera ◽  
Hana Dvořáková ◽  
Jiří Svoboda
Keyword(s):  
Double Bond ◽  
Carboxylic Acid ◽  
Dicarboxylic Acid ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Carboxylic Group ◽  
Methyl Propiolate ◽  
Vinyl Derivatives ◽  
Hydrolysis Of ◽  
Derivatives Of

2-Vinyl- (2) and 3-vinyl[1]benzothieno[3,2-b]furan (3) react with dimethyl acetylenedicarboxylate, methyl propiolate, maleic anhydride, or acrylonitrile endo-selectively as dienes to afford new [1]benzothieno[3,2-b][1]benzofuran derivatives 7-20. cis-Anhydrides 13 and 18 were transformed into dimethyl esters 21 and 22, respectively. It was shown that the base-catalyzed hydrolysis of 13 and 18 is accompanied by rearrangement of double bond in 13 and cis/trans isomerization of carboxylic group. Diesters 21 and 22, and nitriles 20 and 24 were aromatized by treatment with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Selective monodecarboxylation of [1]benzothieno[3,2-b][1]benzofuran-8,9-dicarboxylic acid (26) and [1]benzothieno[3,2-b][1]benzofuran-6,7-dicarboxylic acid (27) afforded [1]benzothieno[3,2-b][1]benzofuran-8-carboxylic acid (28) and [1]benzothieno[3,2-b][1]benzofuran-7-carboxylic acid (29), respectively.

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