ChemInform Abstract: Diels-Alder Reactions with Unsaturated Sulfoxides. Reactions of (Z)-3-Phenylsulfinylprop-2-enoic Acid and Methyl Ester with Furan, 1,3-Diphenyl-isobenzofuran and Anthracene.

1986 ◽  
Vol 17 (36) ◽  
Author(s):  
K. PICKER ◽  
S. M. PROUST ◽  
D. D. RIDLEY
Keyword(s):  
Methyl Ester ◽  
Diels Alder ◽  
Enoic Acid

Effect of catalyst and solvent on the stereochemistry of Diels-Alder reactions between cyclopentadiene and 3-Phenylsulfinylprop-2-enoic acids and methyl esters

1984 ◽  
Vol 37 (8) ◽  
pp. 1677 ◽  
Author(s):  
SM Proust ◽  
DD Ridley
Keyword(s):  
Methyl Ester ◽  
Silica Gel ◽  
Reaction Rate ◽  
Methyl Esters ◽  
Diels Alder ◽  
Enoic Acid ◽  
Stannic Chloride ◽  
Spectroscopic Methods

In Diels-Alder reactions between cyclopentadiene and the isomeric 3-phenylsulfinylprop-2-enoic acids and methyl esters, greatest stereoselectivity (94% d.e.) results when methyl (2)-3-phenylsulfinylprop-2-enoate (7) and benzene solvent are used. The major diastereoisomer, methyl (2-endo,3-endo,S-syn)-3-phenylsulfinylnorborn-5-ene-2-carboxylate (8), also predominates when silica gel or aluminiumchloride catalysts are used, but is formed in lesser amount to the anti-epimer (9) in the presence of stannic chloride. Stereoselectivity of the reaction is decreased as reaction rate accelerates. Mixturesof all four possible diastereoisomers are formed in reactions with (E)-3-phenylsulfinylprop-2-enoic acid (15) and its methyl ester (16), and the ratios of products vary with catalyst and solvent. The stereochemistry at sulfur in these adducts has been correlated unambiguously by chemical and spectroscopic methods.

Diels-Alder Reactions With Unsaturated Sulfoxides. Reactions of (Z)-3-Phenylsulfinylprop-2-Enoic Acid and Methyl-Ester With Furan, 1,3-Diphenylisobenzofuran and Anthracene

1986 ◽  
Vol 39 (4) ◽  
pp. 575 ◽  
Author(s):  
K Picker ◽  
SM Proust ◽  
DD Ridley
Keyword(s):  
Methyl Ester ◽  
High Temperatures ◽  
Low Temperatures ◽  
Diels Alder ◽  
Enoic Acid ◽  
Reaction Conditions ◽  
Thermal Reactions ◽  
Cis And Trans

Methyl (Z)-3-phenylsulfinylprop-2-enoate undergoes Diels -Alder reactions with furan, 1,3-diphenylisobenzofuran and anthracene but chemical and stereochemical courses of the reactions are very dependent upon reaction conditions. Thus, with furan, cis,endo - and cis,exo - adducts are formed exclusively; with 1,3-diphenylisobenzofuran cis,endo - and cis,exo -adducts are formed at low temperatures, whilst the corresponding trans-adducts are formed upon heating; with anthracene where high temperatures are required for condensation cis- and trans-adducts arise together with products from further thermal reactions.

scholarly journals Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene: a general intramolecular Diels–Alder approach to tricyclic sesquiterpenes

1985 ◽  
Vol 63 (4) ◽  
pp. 993-995 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis
Keyword(s):  
Double Bond ◽  
Methyl Ester ◽  
Total Synthesis ◽  
Ring System ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
Total Syntheses ◽  
Methyl Group ◽  
Secondary Hydroxyl ◽  
Selective Hydrogenolysis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.

Total synthesis of (±)-epithuriferic acid methyl ester via Diels–Alder reaction

2016 ◽  
Vol 14 (5) ◽  
pp. 1822-1830 ◽  
Author(s):  
Marek Koprowski ◽  
Piotr Bałczewski ◽  
Krzysztof Owsianik ◽  
Ewa Różycka-Sokołowska ◽  
Bernard Marciniak
Keyword(s):  
Methyl Ester ◽  
Total Synthesis ◽  
Acid Methyl Ester ◽  
Alder Reaction ◽  
Diels Alder ◽  
Natural Sources ◽  
Diels Alder Reaction ◽  
Acid Methyl

The first total synthesis of (±)-epithuriferic acid methyl ester from non-natural sources, in four steps (20% overall yield) is reported in this paper.

A general intramolecular Diels–Alder approach to tricyclic sesquiterpenes: stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene

1987 ◽  
Vol 65 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis ◽  
Alfred W. Hanson
Keyword(s):  
Double Bond ◽  
Methyl Ester ◽  
Ring System ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
Total Syntheses ◽  
Methyl Group ◽  
X Ray ◽  
12 Steps ◽  
Selective Hydrogenolysis

Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl-2-pentenoate 13c affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (14c), which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function by elimination and hydrogenation (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 12 steps from aldehyde 7. A parallel series of reactions employing the isopropyl triene epimer 13a affords (±)-5-epi-sinularene. X-ray analyses of the triene 13a and the adduct 14a are also reported.

Chemical modification of chlorophyll a: synthesis of new regiochemically pure benzoporphyrin and dibenzoporphyrin derivatives

1997 ◽  
Vol 75 (3) ◽  
pp. 262-275 ◽  
Author(s):  
Lifu Ma ◽  
David Dolphin
Keyword(s):  
Photodynamic Therapy ◽  
Methyl Ester ◽  
Chemical Modification ◽  
Chlorophyll A ◽  
Degradation Product ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Pheophorbide A ◽  
Potential Use

Starting from pheophorbide a methyl ester (5), a degradation product of chlorophyll a, routes for the preparation of 3-vinylporphyrins 6 and 9 and of an [A,C]-divinylporphyrin 16 are described. These porphyrins were obtained as a result of chemical modification of 5 on ring D and the exocyclic ring E. Diels–Alder reactions of these (di)vinylporphyrins with dimethyl acetylenedicarboxylate, to afford new regiochemically pure benzoporphyrin derivatives 29 and 30 and dibenzoporphyrin derivative 33 for potential use as sensitizers in photodynamic therapy of tumors, were also investigated. Keywords: Diels–Alder, (di)vinylporphyrins, (di)benzoporphyrins, photodynamic therapy, chlorophyll.

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