Photochemistry of 2,4-Cyclooctadienone I. In Benzene and Toluene

1973 ◽  
Vol 51 (13) ◽  
pp. 2207-2214 ◽  
Author(s):  
Gordon L. Lange ◽  
Eli Neidert
Keyword(s):  
Singlet State ◽  
Alder Reaction ◽  
Diels Alder ◽  
Reactive Intermediate ◽  
Diels Alder Reaction ◽  
Trans Isomerization ◽  
Dimerization Reaction ◽  
Cis And Trans

Irradiation of 2,4-cyclooctadienone (1) in benzene or toluene is shown to give in >80% yield two head-to-head dimers. The ring fusions are shown to occur at the α,β-positions of the dienone with trans-cis and trans-anti-trans stereochemistry. Both dimers may be epimerized to the same product with cis-anti-cis ring fusions. Evidence is presented to show that the singlet state is responsible for the cis-trans isomerization of 1 to the highly reactive intermediate trans, cis-2,4-cyclooctadienone. This intermediate can dimerize in a thermal 2 + 2 cycloaddition or can be generated at −78° and then trapped by 1,3-dienes in a Diels–Alder reaction. A mechanism for the dimerization reaction is discussed.

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.

New synthesis of tetraazachlorins and tetraazabacteriochlorins by Diels–Alder reaction of tetraazaporphine

2000 ◽  
Vol 04 (05) ◽  
pp. 525-531 ◽  
Author(s):  
ELENA A. MAKAROVA ◽  
GALINA V. KOROLYOVA ◽  
OLEG L. TOK ◽  
EVGENY A. LUKYANETS
Keyword(s):  
Electronic Absorption Spectra ◽  
Analysis Data ◽  
Alder Reaction ◽  
Diels Alder ◽  
Elemental Analysis Data ◽  
Tert Butyl ◽  
H Nmr ◽  
Diels Alder Reaction ◽  
Cis And Trans Isomers ◽  
Cis And Trans

The use of the Diels–Alder reaction of unsubstituted tetraazaporphine as dienophile with some dienes of the anthracene series for the synthesis of novel substituted tetraazachlorins, tetraazabacteriochlorins and tetraazaisobacteriochlorins is reported. The condensation of tetraazaporphine with anthracene, 9,10-dimethyl- or 2,6-di(tert-butyl)anthracene in boiling chlorobenzene gives novel dibenzobarreleno-substituted tetraazachlorins 3–5 in yields of up to 71%. When AlCl3 was used as catalyst in the reaction of tetraazaporphine with 2,6-di(tert-butyl) anthracene, the corresponding cis- and trans-dibenzobarreleno-substituted tetraazabacteriochlorins 6a and 6b were obtained. The reaction of tetraazaporphine with the more active diene 2,3-benzanthracene at 130°C gives mainly benzonaphtho[2,3-b]barreleno-substituted tetraazachlorin 7, while the same reaction conducted at 220°C led to a mixture of cis- and trans isomers of tetraazabacteriochlorins 8a and 8b and tetraazaisobacteriochlorins 9a and 9b. The products were characterized using elemental analysis data and mass, 1H NMR and visible spectra. The effect of hydrogenation of one or two double bonds of the tetraazaporphine macrocycle on the electronic absorption spectra is discussed.

Synthesis of chiral trans-syn-cis and trans-anti-trans [6.6.6] tricycles by transannular Diels-Alder reaction

Tetrahedron ◽  
1999 ◽  
Vol 55 (45) ◽  
pp. 13037-13050 ◽  
Author(s):  
Rico Lavoie ◽  
András Toró ◽  
Pierre Deslongchamps
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Cis And Trans

Stereochemically controlled syntheses of some bicyclo[n.3.0]alkane-1-carboxylic acids

1978 ◽  
Vol 56 (1) ◽  
pp. 93-98 ◽  
Author(s):  
E. W. Warnhoff ◽  
W. T. Tai ◽  
Y. C. Toong
Keyword(s):  
Carboxylic Acids ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ring Fusion ◽  
Diels Alder Reaction ◽  
Cyclopentane Ring ◽  
Methods Of Synthesis ◽  
Cis And Trans

Stereospecific methods of synthesis of some cis- and trans-bicyclo[n.3.0]alkane-1-carboxylic acids are described, specifically 5a, 5b, and 11. The cis ring fusion is insured by use of the Diels–Alder reaction, and the trans ring fusion is fixed by the necessity of a cis attachment of an intermediate five-membered cyclic lactamol to the existing cyclopentane ring in 9.

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>

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