ChemInform Abstract: Synthetic Approaches to Phorbols via the Intramolecular Diels-Alder Reaction of Furans: Stereocontrol of the A-B Ring Junction.

ChemInform ◽  
1990 ◽  
Vol 21 (44) ◽  
Author(s):  
L. M. HARWOOD ◽  
G. JONES ◽  
J. PICKARD ◽  
R. M. THOMAS ◽  
D. WATKIN
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Ring Junction ◽  
Synthetic Approaches

Synthetic Approaches towards [1]Benzopyrano [4,3-b]Thieno[2,3-e]Pyridines via Intramolecular Diels-Alder Reactions of 1,2,4-Triazines

2002 ◽  
Vol 2002 (2) ◽  
pp. 60-61 ◽  
Author(s):  
Yehia A. Ibrahim ◽  
Balkis Al-Saleh
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Synthetic Approaches

Efficient syntheses are reported of [1]benzopyrano[4,3-b]thieno[2,3-e]pyridines (20), by the application of an intramolecular Diels–Alder reaction employing the intermediate appropriately designed functionalised thieno [3,2-e][1,2,4]triazines.

scholarly journals Synthetic approaches to haplophytine. 2. Synthesis of 4-methylamino-1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)butan-1-one

1983 ◽  
Vol 61 (6) ◽  
pp. 1126-1131 ◽  
Author(s):  
David Aaron Schwartz ◽  
Peter Yates
Keyword(s):  
Furan Ring ◽  
Alder Reaction ◽  
Diels Alder ◽  
Acid Moiety ◽  
Diels Alder Reaction ◽  
Synthetic Approaches

Approaches to the synthesis of compounds related to the 7-aryl-7-[3-(1-hydroxy-2-aminophenyl)]-9-methylamino-5,6-dioxononanoic acid moiety (3) of the alkaloid haplophytine and its dihydrobromide are described. Treatment of the dianion of phenyl (o-pivaloylamidophenyl)methane with 2-furancarboxaldehyde followed by oxidation of the resulting alcohol gives 1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)ethanone (14). This on allylation gives 1-allyloxy-1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)ethene (20), which on being heated at 80–95 °C undergoes an intramolecular Diels–Alder reaction. Heating the resulting product or 20 at 165 °C converts them to the C-allylation product of 14, 1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)pent-4-en-1-one (22). Oxidation of 22 gives 4-(2-furoyl)-1,2,3,4-tetrahydro-4-phenyl-1-pivaloyl-2-quinolinol, which on Borch reduction gives 4-methylamino-1-(2-furanyl)-2-phenyl-2-(2-pivaloylamidophenyl)butan-1-one (24) and 2-(2-furanyl)-1-methyl-3-phenyl-3-(2-pivaloylamidophenyl)pyrrolidine. Compound 24 is a potential advanced intermediate for the synthesis of compounds related to 3. Experiments directed to the incorporation of a methoxyl or methylthio substituent at the C-5 position of the furan ring of 24 are also described.

ChemInform Abstract: Synthetic Approaches Towards Phorbols via the Ultra-High-Pressure Mediated Intramolecular Diels-Alder Reaction of Furans (IMDAF): Effect of Furan Substitution.

ChemInform ◽  
2010 ◽  
Vol 30 (34) ◽  
pp. no-no
Author(s):  
Angela C. Brickwood ◽  
Michael G. B. Drew ◽  
Laurence M. Harwood ◽  
Tsutomu Ishikawa ◽  
Pierre Marais ◽  
...  
Keyword(s):  
High Pressure ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ultra High Pressure ◽  
Diels Alder Reaction ◽  
Synthetic Approaches

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.

Synthetic Approaches towards [1]Benzopyrano [4,3-b]Thieno[2,3-e]Pyridines via Intramolecular Diels-Alder Reactions of 1,2,4-Triazines

2002 ◽  
Vol 2002 (2) ◽  
pp. 60-61 ◽  
Author(s):  
Yehia A. Ibrahim ◽  
Balkis Al-Saleh
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Synthetic Approaches

Efficient syntheses are reported of [1]benzopyrano[4,3-b]thieno[2,3-e]pyridines (20), by the application of an intramolecular Diels–Alder reaction employing the intermediate appropriately designed functionalised thieno [3,2-e][1,2,4]triazines.

Synthetic Approaches to the Hypothetical Lactone Intermediate in the Pyrolytic Conversion of 8-Methylcyclobuta[a]naphthalene-1,2-dione Into Acenaphthylene

1996 ◽  
Vol 49 (7) ◽  
pp. 793 ◽  
Author(s):  
RFC Brown ◽  
FW Eastwood ◽  
NR Wong
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Intramolecular Alkylation ◽  
Diels Alder Reaction ◽  
Synthetic Approaches

Synthetic approaches to the hypothetical lactone intermediate 8,8a-dihydro-2H-acenaphtho[1,8-bc]furan-2-one (2) based on intramolcular Diels -Alder reaction, and on intramolecular alkylation by diazoacetate groups, were not useful. Generation and pyrolysis of the 9-diazomethylnaphtho[1,2-c]furan-3(1H)-one (19) derived from the corresponding 9-formyl compound (15) gave products including acenaphthylene, consistent with the intermediacy of the lactone (2).

Synthetic Approaches to the Angucycline Antibiotics: A Synthesis of (±)-Hatomarubigin B and C.

1997 ◽  
Vol 50 (4) ◽  
pp. 301 ◽  
Author(s):  
Graham B. Caygill ◽  
David S. Larsen ◽  
Brett S. McFarlane
Keyword(s):  
Natural Products ◽  
Alder Reaction ◽  
Diels Alder ◽  
Racemic Form ◽  
Diels Alder Reaction ◽  
Phenolic Group ◽  
Synthetic Approaches ◽  
Angucycline Antibiotics

The synthesis of the angucycline natural products hatomarubigin B and C in racemic form is described. The key step in the construction of the benz[a]anthraquinone skeleton of these molecules was the Diels–Alder reaction of the acetate of (E,1R*,5R*)-3-(2′-methoxyvinyl)-5-methylcyclohex-2-en-1-ol and 5-acetoxy-8-hydroxy-1,4-naphthoquinone. Methylation of the C11 phenolic group of the resulting cycloadduct, followed by aromatization of the B ring with subsequent deacylation gave (±)-hatomarubigin C. Oxidation of the latter compound with Dess-Martin periodinane, 1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one, gave (±)-hatomarubigin B.

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