ChemInform Abstract: SEMI-EMPIRICAL MO CALCULATIONS ON THE DIELS-ALDER REACTION. I. EHT (EXTENDED HUECKEL THEORY) CALCULATIONS ON THE ENDO-EXO PRODUCT DISTRIBUTION OF SOME DIENE ADDITIONS OF CYCLOPENTADIENE

1976 ◽  
Vol 7 (47) ◽  
pp. no-no
Author(s):  
G. RASCH ◽  
M. SOMMER
Keyword(s):  
Product Distribution ◽  
Alder Reaction ◽  
Diels Alder ◽  
Mo Calculations ◽  
Diels Alder Reaction ◽  
Semi Empirical

Diels–Alder reactions of methyl-N-acyl-α,β-dehydroalaninates with cyclopentadiene

1987 ◽  
Vol 65 (9) ◽  
pp. 2182-2186 ◽  
Author(s):  
M. P. Bueno ◽  
C. Cativiela ◽  
C. Finol ◽  
J. A. Mayoral ◽  
C. Jaime
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Alder Reaction ◽  
Diels Alder ◽  
Wave Functions ◽  
Resonance Spectroscopy ◽  
Mo Calculations ◽  
Total Conversion ◽  
Diels Alder Reaction ◽  
Lower Reactivity

A study has been made of the Diels–Alder reaction of methyl-N-acetyl (and benzoyl)-α,β-dehydroalaninates with cyclopentadiene. In the reaction of methyl-N-acetyl-α,β-dehydroalaninate total conversion is obtained under several conditions, while the N-benzoyl derivative shows a lower reactivity. The stereoselectivity of the reaction is determined by 1H nuclear magnetic resonance spectroscopy. Perturbation MO calculations, using wave functions generated by the MNDO method, are used to rationalize the relative reactivity of the dienophiles and the stereoselectivity observed.

Diels–Alder reaction of androsta-14,16-dien-17-yl acetates with nitroethylene: Product distribution and selected adduct transformations

Steroids ◽  
2013 ◽  
Vol 78 (2) ◽  
pp. 282-287 ◽  
Author(s):  
Alexander V. Baranovsky ◽  
Dmitry A. Bolibrukh ◽  
Vladimir A. Khripach ◽  
Bernd Schneider
Keyword(s):  
Product Distribution ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

Construction of bicyclic tetrahydroisoquinolinones by combination of an IMDAF-ring cleavage reaction of N-allyl-2-furan-2-yl-acetamides

2000 ◽  
Vol 78 (6) ◽  
pp. 749-756 ◽  
Author(s):  
Albert Padwa ◽  
Thomas S Reger
Keyword(s):  
Energy Difference ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ring Cleavage ◽  
Am1 Calculations ◽  
Reaction Conditions ◽  
Intramolecular Cycloaddition ◽  
Tertiary Amide ◽  
Diels Alder Reaction ◽  
Semi Empirical

The intramolecular Diels-Alder reaction of furanyl amides derived from 2-furylacetic acid has been examined. Substrates containing either an imide or tertiary amide linkage between the furan and the dienophile underwent smooth cycloaddition upon thermolysis. By varying the reaction conditions, either the primary cycloadduct or the ring-opened and acetylated product could be isolated in excellent yield. The stereochemical outcome of the IMDAF cycloaddition has the side arm of the tethered alkenyl group oriented syn with respect to the oxygen bridge. Semi-empirical AM1 calculations show that the exo-cycloadduct is 11 kcal lower in energy than the corresponding endo adduct and, presumably, some of this energy difference is reflected in the transition state for the cycloaddition. The IMDAF reaction of N-allyl-[2-(3,4-dimethoxyphenethyl)]-2-furanyl-2-yl-acetamide proceeded in 90% yield upon heating in xylene. The 4+2-cycloadduct undergoes ring-opening on treatment with base and the resulting alcohol was converted into the corresponding benzyl ether. Raney nickel reduction followed by Bischler-Napieralski cyclization furnished the tetracyclic skeleton of the berberine alkaloids.Key words: intramolecular, cycloaddition, Diels-Alder, furanylamide, heterocycle.

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

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>

Natural Products Biosynthesis Involving a Putative Diels-Alder Reaction

2016 ◽  
Vol 20 (22) ◽  
pp. 2421-2442 ◽  
Author(s):  
Kévin Cottet ◽  
Maria Kolympadi ◽  
Dean Markovic ◽  
Marie-Christine Lallemand
Keyword(s):  
Natural Products ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction
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