A Domino Ring-Closure Followed by Retro-Diels-Alder Reaction for the Preparation of Pyrimido[2,1-a]isoindole Enantiomers

2016 ◽  
Vol 2016 (21) ◽  
pp. 3519-3527 ◽  
Author(s):  
Beáta Fekete ◽  
Márta Palkó ◽  
István Mándity ◽  
Matti Haukka ◽  
Ferenc Fülöp
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Ring Closure ◽  
Diels Alder Reaction

scholarly journals Studies Towards the Synthesis of Salvinorin A

2006 ◽  
Vol 59 (5) ◽  
pp. 340 ◽  
Author(s):  
Anthony R. Lingham ◽  
Helmut M. Hügel ◽  
Trevor J. Rook
Keyword(s):  
Stereoselective Synthesis ◽  
Aqueous Media ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ring Closure ◽  
Salvinorin A ◽  
One Pot ◽  
Diels Alder Reaction ◽  
Opioid Receptor Agonist ◽  
Ether Bridge

Salvinorin A 1, a psychoactive neoclerodane diterpenoid from the Mexican sage S. divinorum, has gained interest as a selective κ-opioid receptor agonist. Non-racemic 3-furylamines 9a and 9b have been prepared from (+)-pseudoephedrine and (–)-ephedrine for application in the stereoselective synthesis of the ketone ring of 1. Diels–Alder reaction of 9b with methyl acrylate in aqueous media, followed by selective ether bridge cleavage, has allowed access to the cyclohexenone 17 with preservation of stereochemistry at C2. A model route to the lactone ring has also been achieved through a one-pot deconjugation/esterification procedure of 2-bromocrotonyl chloride 20 to the furyl alcohol 19 followed by Reformatski-mediated ring closure.

Stereoinformation Relay: Coupling Diastereoselectivity of a Thermal Diels‐Alder Reaction with the Photochemical Ring‐Closure of Diarylethenes

ChemPhotoChem ◽  
2019 ◽  
Vol 3 (6) ◽  
pp. 461-466
Author(s):  
Kevin Broi ◽  
Anne Fuhrmann ◽  
André Dallmann ◽  
Fabian Berger ◽  
Stefan Hecht
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Ring Closure ◽  
Diels Alder Reaction

DFT studies on the diastereoselectivity and regioselectivity of multicomponent domino Knoevenagel/Diels–Alder reaction

2020 ◽  
Vol 19 (02) ◽  
pp. 2050005 ◽  
Author(s):  
Mina Attarbashi ◽  
Nader Zabarjad Shiraz ◽  
Marjaneh Samadizadeh
Keyword(s):  
Gas Phase ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ring Closure ◽  
Dft Studies ◽  
Acid Base ◽  
Bond Rotation ◽  
Diels Alder Reaction ◽  
Difference Formula ◽  
State Formula

In this study, mechanism and stereochemistry of multicomponent domino Knoevenagel/Diels–Alder reaction were investigated theoretically. Structures of reagents, transition states, intermediates, and products were optimized at M062X/6-31[Formula: see text]G(d,p) level of theory. Although the mechanism of this reaction involved several processes, including bond rotation, isomerization, asymmetric cycloaddition, acid-base, and nucleophile–electrophile competitions, critical processes were studied to provide a clearer picture of the mechanism of this valuable reaction in terms of stereochemistry considerations. According to the results, the ring closure step of reaction performed via a polar Dield-Alder mechanism, having enthalpy at approximately 40[Formula: see text]kcal/mol. The diastereoselectivity of the reaction was controlled by the interaction of dienophile with the less hindered face of diene through a more stable endo transition state ([Formula: see text] and 27.31 in methanol and gas phase, respectively). HSAB criteria could explain the regioselectivity of this reaction by considering the least softness difference ([Formula: see text]) for interacting C-atoms based on Hirshfeld populations. The result was the creation of cis-spiro cyclohexanone under kinetic and thermodynamic controls as a predominant diastereoselective and regioselective product.

ChemInform Abstract: A Domino Ring-Closure Followed by Retro-Diels-Alder Reaction for the Preparation of Pyrimido[2,1-a]isoindole Enantiomers.

ChemInform ◽  
2016 ◽  
Vol 47 (43) ◽  
Author(s):  
Beata Fekete ◽  
Marta Palko ◽  
Istvan Mandity ◽  
Matti Haukka ◽  
Ferenc Fueloep
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Ring Closure ◽  
Diels Alder Reaction

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

Aza-Diels-Alder Reaction Between 1,2-Diaza-1,3-dienes and β-Aryl-α,β-unsaturated Carbonyl Compounds. Easy One-pot Entry to 2’-Oxo-imidazo[1’,5’- f]tetrahydropyridazine

2014 ◽  
Vol 10 (6) ◽  
pp. 951-960
Author(s):  
Orazio Attanasi ◽  
Luca Bianchi ◽  
Maurizio D’Auria ◽  
Gianfranco Favi ◽  
Fabio Mantellini ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Alder Reaction ◽  
Diels Alder ◽  
One Pot ◽  
Diels Alder Reaction
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