A synthesis and some reactions of 7-Oxabicyclo[2.2.1]heptan-2-one

1983 ◽  
Vol 36 (12) ◽  
pp. 2473 ◽  
Author(s):  
J Moursounidis ◽  
D Wege
Keyword(s):  
Thermal Decomposition ◽  
Alder Reaction ◽  
Diels Alder ◽  
Acid Mixture ◽  
Diels Alder Reaction ◽  
Reaction Proceeds ◽  
Atom Migration ◽  
Acyl Azide ◽  
Mild Hydrolysis ◽  
Hydrolysis Of

Diels-Alder reaction between furan and α-chloroacrylonitrile gives a mixture of exo-2-chloro-and endo-2-chloro-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitrile (4) and (5). Mild hydrolysis affords the corresponding α-chloro acid mixture, from which the endo carboxylic acid may be removed through iodo lactone formation. Catalytic hydrogenation of (4) and (5) followed by hydrolysis, acyl azide formation, Curtius rearrangement, and hydrolysis of the resulting mixture of a-chloro isocyanates yields 7-oxabicyclo[2.2.l]heptan-2-one (1) in preparatively useful amounts. Reduction of (1) gives only endo alcohol, and Baeyer-Villiger reaction proceeds with exclusive bridgehead atom migration. Thermal decomposition of the sodium salt of the p-toluenesulfonylhydrazone of (1) affords 7-oxatricyclo[2.2.1 .02,6]heptane.

Tandem Wessely oxidation and intramolecular Diels–Alder reactions. IV. The synthesis of (±)-coronafacic acid

1993 ◽  
Vol 71 (7) ◽  
pp. 995-1001 ◽  
Author(s):  
Peter Yates ◽  
N.K. Bhamare ◽  
Thierry Granger ◽  
T.S. Macas
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Ethoxide ◽  
Alder Reaction ◽  
Diels Alder ◽  
Lead Tetraacetate ◽  
Oxidative Decarboxylation ◽  
Coronafacic Acid ◽  
Diels Alder Reaction ◽  
Mild Hydrolysis ◽  
Hydrolysis Of

Ethyl E-5-(4-ethyl-2-hydroxyphenyl)-2-pentenoate (7), prepared in four steps from m-ethylphenol (9), was converted via Wessely oxidation with lead tetraacetate followed by intramolecular Diels–Alder reaction in boiling xylene to ethyl 1-acetyloxy-6-ethyl-2,3,3a,4,5,7a-hexahydro-8-oxo-1,5-methano-1H-indene-anti-4-carboxylate (16). Hydrogenation of 16 followed by mild hydrolysis gave ethyl 6-ethyloctahydro-1-hydroxy-8-oxo-1,5-methano-1H-indene-anti-4-car-boxylate (24), which on oxidation with periodate gave 4-(ethoxycarbonyl)-6-ethyloctahydro-1-oxo-1H-indene-5-car-boxylic acid (26). Oxidative decarboxylation of this gave a mixture of ethyl 6-ethyl-2,3,3a,6,7,7a-hexahydro-1-oxo-1H-indene-4-carboxylate (31) and ethyl 6-ethyl-2,3,3a,4,7,7a-hexahydro-1-oxo-1H-indene-4-carboxylate (32); the latter was converted to the former by ethanolic sodium ethoxide. Hydrolysis of 31 with hot hydrochloric acid gave (±)-coronafacic acid (4).

4-Aryl-3-substituted Furans

1994 ◽  
Vol 59 (12) ◽  
pp. 2721-2726 ◽  
Author(s):  
Jarmila Štetinová ◽  
Ján Leško ◽  
Miloslava Dandárová ◽  
Rudolf Kada ◽  
Roman Koreň
Keyword(s):  
Thermal Decomposition ◽  
Triple Bond ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Substituted Furans

4-Aryl-3-substituted furans IIIa - IIId were prepared by Diels Alder reaction of 4-phenyloxazole (I) with compounds IIa - IId, containing an activated triple bond, and subsequent thermal decomposition of the cycloadduct.

Dihydrothiophenes.10. The preparation and Diels–Alder reactions of some sulfur and phosphorus-substituted dienophiles and 2-aza-substituted 1,3-dienes

1984 ◽  
Vol 62 (11) ◽  
pp. 2089-2093 ◽  
Author(s):  
John M. McIntosh ◽  
Lilianna Z. Pillon
Keyword(s):  
Thermal Decomposition ◽  
Alder Reaction ◽  
Conjugated Dienes ◽  
Diels Alder ◽  
Diels Alder Reaction

The use of 3-carboxylated 2,5-dihydrothiophenes as the dienophilic component of the Diels–Alder reaction has been investigated. The yields are generally quite low. The formation of conjugated dienes that are aminated at an interior position of the conjugated chain by formation and thermal decomposition of 3-acetamido-2,5-dihydrothiophenes appears to be a viable route to these useful compounds. One example of the Diels–Alder reaction of 2-carboxylated diethyl vinylphosphonates is reported.

The synthesis, isomerization and stability of some enol-lactones

1982 ◽  
Vol 35 (9) ◽  
pp. 1903 ◽  
Author(s):  
IR Doyle ◽  
RA Massy-Westropp
Keyword(s):  
Thermal Decomposition ◽  
Wittig Reaction ◽  
Alder Reaction ◽  
Diels Alder ◽  
Kinetic Control ◽  
Relative Stabilities ◽  
Diels Alder Reaction ◽  
Wittig Reactions

The photoisomerization of enol-lactones is described. Thermal decomposition of (E) and (Z) ethyl 3-oxo-1,3,3aβ,4α,7α,7aβ-hexahydro-4,7-methanoisobenzofran-1-yideneacetates provides a good route to (E) and (Z) ethyl 5-oxo-2,5-dihydrofuran-2-ylideneacetates. Other examples of this retro-Diels-Alder reaction are reported. The relative stabilities of (E) and (Z) enol-lactones from the Wittig reaction between substituted succinic anhydrides and ethoxycarbonylmethylenetriphenylphosphorane have been determined. These Wittig reactions are under kinetic control.

scholarly journals Direct Diels-Alder reaction of chitin derived 3-acetamido-5-acetylfuran

2022 ◽  
Author(s):  
Rafael Gomes ◽  
Juliana Pereira ◽  
João Ravasco ◽  
João Vale ◽  
Fausto Queda
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Fine Tuning ◽  
Reduced Form ◽  
Partial Hydrolysis ◽  
Reaction Conditions ◽  
Diels Alder Reaction ◽  
Direct Use ◽  
Kinetics Of ◽  
Hydrolysis Of

The Diels-Alder (DA) reaction of biomass derived furans is an emerging technology for the preparation of new molecular entities and “drop-in” commodity chemicals. In this work we address the challenge of the direct use of electron-poor furanic platforms as dienes through the use of an unexplored chitin derived furan, 3-acetamido-5-acetylfuran (3A5AF). The 3-acetamido group promoted a remarkable increase in the kinetics of the DA allowing for the preparation of 7-oxanorbornenes (7-ONB) at 50 ºC. Partial hydrolysis of the enamide to hemi-acylaminals was possible upon fine tuning of the reaction conditions, disabling retro-DA processes. Finally, DA reaction of the reduced form of 3A5AF allowed quantitative formation of 7-ONB in aqueous condition after 10 minutes. Certanly these are the first steps for expanding the toolbox of chitin derived 3A5AF as diene.

scholarly journals TiCl3 as a New Catalyst for the Imino Diels-Alder Reaction

2006 ◽  
Vol 1 (9) ◽  
pp. 1934578X0600100
Author(s):  
Narayan V. Mayekar ◽  
Sandip K. Nayak ◽  
Subrata Chattopadhyay
Keyword(s):  
Ambient Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Trans Isomers ◽  
Effective Catalyst ◽  
Diels Alder Reaction ◽  
Cis And Trans Isomers ◽  
Reaction Proceeds ◽  
Cis And Trans

Titanium(III) chloride was found to be an effective catalyst for the imino Diels-Alder reaction between an imine (generated in situ) and an activated alkene in acetonitrile at ambient temperature. The reaction proceeds smoothly to afford the corresponding adduct as a mixture of chromatographically separable cis- and trans isomers in moderate to good yields.

scholarly journals Oxidative Asymmetric Formal Aza-Diels–Alder Reactions of Tetrahydro-β-carboline with Enones in the Synthesis of Indoloquinolizidine-2-ones

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2228 ◽  
Author(s):  
Xiang Wu ◽  
Shi-Bao Zhao ◽  
Lang-Lang Zheng ◽  
You-Gui Li
Keyword(s):  
Oxidative Dehydrogenation ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diastereoselective Synthesis ◽  
Butyl Hydroperoxide ◽  
Unsaturated Ketones ◽  
Tert Butyl ◽  
Diels Alder Reaction ◽  
Tert Butyl Hydroperoxide ◽  
Reaction Proceeds

Ru-catalyzed tandem amine oxidative dehydrogenation/formal aza-Diels–Alder reaction for enantio- and diastereoselective synthesis of indoloquinolizidine-2-ones from tetrahydro-β-carbolines and α,β-unsaturated ketones is described. The reaction proceeds via tandem ruthenium-catalyzed amine dehydrogenation using tert-butyl hydroperoxide (TBHP) as the oxidant and a chiral thiourea-catalyzed formal aza-[4 + 2] cycloaddition, providing a step-economical strategy for the synthesis of these valuable heterocyclic products.

Hetero-Diels-Alder Reactions of 2H-Phospholes with Allenes: Synthesis and Functionalization of 6-Methylene-1-phosphanorbornenes

2021 ◽  
Author(s):  
Keke Zhang ◽  
Qiao-Yu Zhang ◽  
Donghui Wei ◽  
Rongqiang Tian ◽  
Zheng Duan
Keyword(s):  
Double Bond ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Reaction Proceeds ◽  
High Yields

The phospha-Diels–Alder reaction between 2H-phospholes and arylallenes afford 6-methylene-1-phosphanorbornenes in high yields and excellent regioselectivity. This Diels–Alder reaction proceeds at the internal C=C double bond of allenes selectively. The DFT...

Pyrrole Chemistry. XV. The Chemistry of Some 3,4-Disubstituted Pyrroles

1973 ◽  
Vol 51 (7) ◽  
pp. 1089-1098 ◽  
Author(s):  
John Kington Groves ◽  
Niven Eddy Cundasawmy ◽  
Hugh John Anderson
Keyword(s):  
Raney Nickel ◽  
Aluminum Chloride ◽  
Alder Reaction ◽  
Subsequent Treatment ◽  
Diels Alder ◽  
Partial Hydrolysis ◽  
Antimitotic Agent ◽  
Proton Abstraction ◽  
Diels Alder Reaction ◽  
Hydrolysis Of

The syntheses of a variety of 3,4-disubstituted pyrroles including the antimitotic agent Verrucarin E are described. 3,4-Pyrroledicarboxylic esters were prepared through a Diels–Alder reaction. Partial hydrolysis of the diesters gave the 4-ester-3-acids which were modified to achieve the synthesis of a variety of unsymmetrically 3,4-disubstituted pyrroles. Raney nickel reduction of a thiolester gave hydroxymethyl under conditions which left acyl or carbalkoxy substituents unaffected. Pyrrole reactions involving carbanionic reagents are complicated by 1-proton abstraction. Therefore, when necessary, the nitrogen was protected by an N-benzyloxymethyl substituent which can be cleaved to the N-hydroxymethyl derivative by aluminum chloride or by hydrogenolysis. Subsequent treatment with benzyltrimethylammonium hydroxide gave back the pyrrole.

Synthesis of highly functionalized naphthoate precursors to damavaricin D — Observation of kinetically stable benzocyclohexadienones in the bromination reactions of highly functionalized β-naphthol derivatives

2001 ◽  
Vol 79 (11) ◽  
pp. 1711-1726
Author(s):  
William R Roush ◽  
David J Madar ◽  
D Scott Coffey
Keyword(s):  
Total Synthesis ◽  
Chloride Ion ◽  
Alder Reaction ◽  
Diels Alder ◽  
Substitution Reactions ◽  
Diels Alder Reaction ◽  
Reaction Proceeds ◽  
Bromide Ion ◽  
Aromatic Bromination ◽  
Naphthol Derivatives

Selective syntheses of the highly substituted bromonaphthoates 4a, 4b, 19, and 22 are reported. These compounds were targeted as precursors to the naphthoquinone nucleus of damavaricin D; compound 22 ultimately was used in the successful total synthesis. The synthesis of 22 features the Diels–Alder reaction of the oxygenated diene 5 and 2,6-dibromo-3-methylbenzoquinone 6 to establish the core naphthalenic unit. The quinone was protected throughout this synthesis as a 1,4-bis-methoxymethyl-1,4-dihydroquinone (see 36). The C-2-carboalkoxy group of 22 was added by carboxylation of the aryllithium intermediate generated from 36, and protected as a β-trimethylsilylethyl ester. Finally, the C-8-Br substituent was introduced by NBS bromination of 38. This reaction proceeds by way of bromobenzocyclohexadienone 39. Related bromobenzo-cyclohexadienones 13 and 29 were observed in the NBS brominations of the highly functionalized β-naphthyl MOM ethers 11 and 28. The bromobenzocyclohexadienones 29 and 39 undergo facile substitution reactions with chloride ion and reduction with bromide ion at rates competitive with base-promoted aromatization. The surprising kinetic stability of these intermediates is attributed to a combination of steric and stereoelectronic factors.Key words: damavaricin D, naphthoate precursors, kinetically stable benzocyclohexadienones, aromatic bromination.

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