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.

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.

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.

scholarly journals Studies towards the Synthesis of the Antibiotic Tetrodecamycin

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1117-1121
Author(s):  
Victor Lee ◽  
Jing He ◽  
Jack Baldwin
Keyword(s):  
Natural Product ◽  
Wittig Reaction ◽  
Alder Reaction ◽  
Membered Ring ◽  
Diels Alder ◽  
Acid Moiety ◽  
Tetronic Acid ◽  
Diels Alder Reaction

A study towards the natural product tetrodecamycin is reported. A modified Schlosser–Wittig reaction was utilized to prepare the precursor for the subsequent intramolecular Diels–Alder reaction, which delivered the trans-decalin ring of the natural product. The tetronic­ acid moiety of the molecule was prepared by a Dieckmann cyclization­. The cyclization of the tetronic acid to the trans-decalin double­ bond to form a seven-membered ring was examined.

scholarly journals A DFT investigation of Diels-Alder reaction of ethyl propiolate to the cage-annulated hexacyclo[7.5.2.01,6.06,13.08,12.010,14]hexadeca-2,4-diene-7,16-dione

2018 ◽  
Vol 83 (7-8) ◽  
pp. 837-846
Author(s):  
Abdurrahman Atalay ◽  
Riza Abbasoglu
Keyword(s):  
Theoretical Calculations ◽  
Cycloaddition Reaction ◽  
Dft Method ◽  
Alder Reaction ◽  
Diels Alder ◽  
Frontier Molecular Orbital ◽  
Kinetic Control ◽  
Diels Alder Reaction ◽  
Potential Map ◽  
Good Agreement

The Diels?Alder (DA) reaction between the cage-annulated diene hexacyclo[7.5.2.01,6.06,13.08,12.010,14]hexadeca-2,4-diene-7,16-dione (HHDD) with a cyclohexa-1,3-diene moiety and ethyl propiolate (EP) dienophile was investigated by the DFT method at the B3LYP/6-31+G(d,p) level to elucidate the mechanism and regioselectivity features of the reaction. The geometrical and electronic structures of the caged diene HHDD and EP were studied at B3LYP/6-31+G(d,p) level. In order to identify facial- and regio-selectivity of the DA reaction of HHDD and EP, the frontier molecular orbital (FMO) interactions of the reactants according to the FMO theory, and the molecular electrostatic potential map of HHDD were examined. The potential energy surface (PES) of the related DA reaction was calculated, and optimizations of transition states and of products corresponding to critical points on the PES were performed at the B3LYP/6-31+G(d,p), and their configurations were determined. In addition, the thermodynamic and kinetic parameters of each possible cycloaddition reaction were calculated using the B3LYP/6-31+G(d,p) method to determine whether the reaction occurs under thermodynamic or kinetic control. The thermochemical results showed that the related DA cycloaddition proceeds under kinetic control, and the activation energies of syn cycloadditions are clearly lower than that of anti cycloadditions. The theoretical calculations are in good agreement with experimental results.

The Diels-Alder Reaction of 2-Ethenyl-1,4-Benzodioxin: A New and Simple Synthesis of Bisaryl Ethers

Synlett ◽  
1989 ◽  
Vol 1989 (01) ◽  
pp. 30-32
Author(s):  
Thomas V. Lee ◽  
Alistair J. Leigh ◽  
Christopher B. Chapleo
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Simple Synthesis ◽  
Diels Alder Reaction

Asymmetric aza-Diels-Alder reaction of Danishefsky’s diene with imines in a chiral reaction medium

2006 ◽  
Author(s):  
Giang Vo-Thanh ◽  
Bruce Pégot ◽  
Olivier Van Buu ◽  
Didier Gori
Keyword(s):  
Reaction Medium ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Danishefsky's Diene

The intermolecular anthracene-transfer in a regiospecific antipodal C60 difunctionalization

2020 ◽  
Author(s):  
Radu Talmazan ◽  
Klaus R. Liedl ◽  
Bernhard Kräutler ◽  
Maren Podewitz
Keyword(s):  
Noncovalent Interactions ◽  
Interaction Model ◽  
Alder Reaction ◽  
Diels Alder ◽  
Stacking Interactions ◽  
Pi Stacking ◽  
Diels Alder Reaction ◽  
Double Decker ◽  
Anthracene Molecule ◽  
New Strategies

We analyze the mechanism of the topochemically controlled difunctionalization of C60 and anthracene, where an anthracene molecule is transferred from one C60 monoadduct to another one under exclusive formation of equal amounts of C60 and the difficult to make antipodal C60 bisadduct. Our herein disclosed dispersion corrected DFT studies show the anthracene transfer to take place in a synchronous retro Diels-Alder/Diels-Alder reaction: an anthracene molecule dissociates from one fullerene under formation of an intermediate, while already undergoing stabilizing interactions with both neighboring fullerenes, facilitating the reaction kinetically. In the intermediate, a planar anthracene molecule is sandwiched between two neighboring fullerenes and forms equally strong "double-decker" type pi-pi stacking interactions with both of these fullerenes. Analysis with the distorsion interaction model shows that the anthracene unit of the intermediate is almost planar with minimal distorsions. This analysis sheds light on the existence of noncovalent interactions engaging both faces of a planar polyunsaturated ring and two convex fullerene surfaces in an unprecedented 'inverted sandwich' structure. Hence, it sheds light on new strategies to design functional fullerene based materials.<br>

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