scholarly journals Two-Carbon Ring Enlargement of Five-, Six-, and Seven-Membered 1-Aza-2-vinylcycloalk-2-enes with Dimethyl Acetylenedicarboxylate and Subsequent Thermal Isomerization Reactions

2006 ◽  
Vol 61 (4) ◽  
pp. 385-395 ◽  
Author(s):  
Gerhard Maas ◽  
Robert Reinhard ◽  
Hans-Georg Herz
Keyword(s):  
Elevated Temperatures ◽  
Alder Reaction ◽  
Thermal Isomerization ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
Ring Enlargement ◽  
Diels Alder Reaction ◽  
Carbon Ring ◽  
Electrocyclic Reaction

2-Aminodienes, in which the enamine function is incorporated in a five-, six-, or seven-membered ring, react with dimethyl acetylenedicarboxylate in a sequence of [2+2] cycloaddition and electrocyclic ring-opening to form the two-carbon ring expanded unsaturated heterocycles, i.e., 3,4- dicarboxylate substituted 6,7-dihydro-1H-azepines 3, 8 and 21, 1,6,7,8-tetrahydroazocines 22, and 6,7,8,9-tetrahydro-1H-azonines 13. Similarly, 2-[(2-thienyl)ethynyl]-4,5,6,7-tetrahydro-1H-azepine 9 is converted into 2-[(2-thienyl)ethynyl]-6,7,8,9-1H-azonine-3,4-dicarboxylate 10 which was characterized by X-ray structure determination. The eight- and nine-membered azaheterocycles 22 and 13, which have not been isolated, undergo thermal isomerization at elevated temperatures. Thus, ring contraction by a 6π-electrocyclic reaction takes place for N-methyl substituted azonine 13, while the N-allyl moiety of azocines 22 engages in an intramolecular Diels-Alder reaction or a 1,7- electrocyclization reaction

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.

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.

Diels-Alder reaction of pyrrole with dimethyl acetylenedicarboxylate

1978 ◽  
Vol 43 (19) ◽  
pp. 3727-3729 ◽  
Author(s):  
Chang Kiu Lee ◽  
Chi Sun Hahn ◽  
Wayland E. Noland
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Diels Alder Reaction

Diels-Alder Reaction of Enaminodithiocarboxylate Derivatives with Dimethyl Acetylenedicarboxylate

Heterocycles ◽  
1975 ◽  
Vol 3 (1) ◽  
pp. 85 ◽  
Author(s):  
Goro Kobayashi ◽  
Kzumichi Mizuyama ◽  
Yoshinori Miyake ◽  
Yoshinori Tominaga ◽  
Yoshiro Matsuda
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Diels Alder Reaction

Vinylindenes and Some Heteroanalogs in the Diels-Alder Reaction. X. Dibenzofurans From 3-Vinylbenzofurans

1991 ◽  
Vol 44 (8) ◽  
pp. 1085 ◽  
Author(s):  
JR Pearson ◽  
QN Porter
Keyword(s):  
Maleic Anhydride ◽  
Alder Reaction ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Diels Alder Reaction

3-Vinylbenzofuran, 3-isopropenylbenzofuran and 2-methyl-3-vinylbenzofuran give normal [4π+2π] adducts with ethenetetracarbonitrile, accompanied, in the case of the last named diene, by the isomeric cyclobutane. Normal adducts also result from these dienes and 4-phenyl-1,2,4-triazoline-3,5-dione, and from 3-vinylbenzofuran and both maleic anhydride and N- phenylmaleimide. 3-Vinylbenzofuran gives the rearranged adduct dimethyl 1,2-dihydrodibenzofuran-3,4-dicarboxylate with dimethyl acetylenedicarboxylate.

Vinylindenes and some heteroanalogues in the Diels-Alder reaction. II. Substituted fluorenes from 3-vinylindenes

1977 ◽  
Vol 30 (5) ◽  
pp. 1061 ◽  
Author(s):  
R Bergamasco ◽  
QN Porter
Keyword(s):  
Mass Spectrometry ◽  
Maleic Anhydride ◽  
Alder Reaction ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Diels Alder Reaction

3-Vinylindene, 2-methyl-3-vinylindene and 3-isopropenylindene give normal, photostable adducts with ethenetetracarbonitrile by a Diels- Alder process. The first diene gives adducts with maleic anhydride, N- phenylmaleimide and dimethyl acetylenedicarboxylate. Where there is stereochemical ambiguity the adducts are shown by mass spectrometry to be exclusively endo. Two heterocyclic analogues are formed from 3- vinylindene with p-toluenesulphonyl cyanide and N-sulphinyl-p- toluenesulphonamide.

Influence of Lewis acids on the Diels–Alder reaction. III. Rearrangement of dimethyl N-carbomethoxy-7-azabicyclo[2.2.1]2,5-heptadiene-2,3-dicarboxylate adducts to dimethyl N-carbomethoxy-3-aminophthalates

1970 ◽  
Vol 48 (9) ◽  
pp. 1472-1474 ◽  
Author(s):  
R. C. Bansal ◽  
A. W. McCulloch ◽  
A. G. McInnes
Keyword(s):  
Aluminum Chloride ◽  
Lewis Acids ◽  
Alder Reaction ◽  
Diels Alder ◽  
Prolonged Treatment ◽  
Dimethyl Acetylenedicarboxylate ◽  
Diels Alder Reaction ◽  
Convenient Route

Aluminum chloride accelerates the Diels–Alder reactions of 2- or 2,5-substituted N-carbomethoxypyrroles with dimethyl acetylenedicarboxylate, and also catalyzes rearrangement of the N-carbomethoxy-7-azanorbornadiene adducts to 6- and 4,6-substituted dimethyl N-carbomethoxy-3-aminophthalates. Aromatization of the corresponding adduct of N-carbomethoxypyrrole only occurs on prolonged treatment with BF3. The procedure promises to be a convenient route for the synthesis of polysubstituted anilines.

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