63678-00-2Relevant academic research and scientific papers
α-Methylene Cyclic Carbonate as a Conjunctive Agent for Aromatic Aldehydes
Inoue, Yoshio,Matsushita, Koichi,Yen, I-Fang,Imaizumi, Shin
, p. 1377 - 1378 (2007/10/02)
α-Methylene cyclic carbonate undervent dacarboxylative cycliaddition to aromatic aldehydes to yield dihydrofuranone derivatives in the presence of a dicationic palladium complex.
A radical cyclisation route to bullatenone, a natural 3(2H)-furanone
Srikrishna
, p. 479 - 480 (2007/10/02)
A simple route to bullatenone (3) starting from styrene, via the radical cyclisation of the bromoalkyne 6 to 3-methylenetetrahydrofuran 7, is described.
Stereoelectronic effects in ring closure reactions: the 2'-hydroxychalcone-flavanone equilibrium, and related systems
Brennan, Colin M.,Hunt, Ian,Jarvis, Terence C.,Johnson, C. David,McDonnell, Peter D.
, p. 1780 - 1785 (2007/10/02)
The 2'-hydroxychalcone (2-HOC6H4COCH=CHC6H4X)-flavanone equilibrium in trifluoroacetic acid (TFA) has been examined.The influence of substituents X on the rate of attainment of equilibrium shows that the 6-endo-trig mode of ring closure by Michael addition is disallowed, by demonstrating a negative ρ value for the reaction rate when X is varied.Reaction therefore proceeds either on the carbonyl-protonated form, which allows twisting about the 2,3 double bond, its double bond character being reduced by resonance, or through direct rate-limiting protonation on the 2,3-double bond.Either pathway permits the allowed 6-exo-trig mode of ring closure to be followed.Alternative mechanism involving intermolecular Michael addition of trifluoroacetate, followed by intramolecular 6-exo-tet displacement are considered.Such Michael adducts can be detected in the ring closures of 2-crotonyl-4-methylphenol and 4,4-dimethyl-1-(2-hydroxyphenyl)-2-penten-1-one in TFA, but they do not appear to lie on the main pathway, because the reaction proceed with equal facility in methanesulphonic acid/chloroform medium, which does not contain a suitable nucleophile for such a mechanism.Further important mechanistic information is given by studying the reactions in TFA-d, together with measurements on the (E)-2-methyl-3-oxo-5-arylpent-4-en-2-ol and flight during the rate-limiting step, and provide evidence against the mechanism involving a preequilibrium carbonyl protonation, such as in the Nazarov rearrangement of 3'-methoxychalcones, where KH/kD is ca. 0.7.Some results are also reported for ring closure of the 2-aminochalcones in TFA.
Rhodium Acetate Catalyzes the Addition of Carbenoids α- to Ether Oxygens
Adams, Julian,Poupart, Marc-Andre,Grenier, Louis,Schaller, Chris,Ouimet, Nathalie,Frenette, Richard
, p. 1749 - 1752 (2007/10/02)
Diazo-carbonyl compounds, when catalyzed by rhodium acetate, insert preferentially adjacent to ether oxygens.This phenomenon was exploited to develop a synthesis of 3(2H)-furanones.
Regiocontrolled Formation of 4,5-Dihydro-3(2H)-furanones from 2-Butyne-1,4-diol Derivatives. Synthesis of Bullatenone and Geiparvarin
Saimoto, Hiroyuki,Hiyama, Tamejiro,Nozaki, Hitosi
, p. 3078 - 3087 (2007/10/02)
Two new methods for selective hydration of 1,1,4-trisubstituted 2-butyne-1,4-diols (1) to give 4,5-dihydro-3(2H)-furanone derivatives are reported.The first involves selective monoacetylation of the less hindered hydroxyl group of 1 followed by Ag(I)-cata
Reversal of Electronic Effects between Inter- and Intra-molecular Michael Addition Reactions
Ellis, Graham W. L.,Johnson, C. David,Rogers, David N.
, p. 36 - 37 (2007/10/02)
Measurement of the rates of cyclisation of (E)-2-methyl-3-oxo-5-phenylpent-4-en-2-ol and its p-methoxy-derivative in trifluoroacetic acid, together with the rates of the reverse reaction, indicates an influence of stereoelectronic origin which is not present in intermolecular Michael additions.
Synthesis and Reactions of Simple 3(2H)-Furanones
Smith, Amos B.,Levenberg, Patricia A.,Jerris, Paula J.,Scarborough, Robert M.,Wovkulich, Peter M.
, p. 1501 - 1513 (2007/10/02)
Interest in the total synthesis of natural product antitumor agents which have as a central structural element the 3(2H)-furanone ring system has led to the development of an efficient general synthesis of a variety of simple 3(2H)-furanones.The strategy
Synthesis of functionalized tetrahydrofurans
Semple, J.Edward,Guthrie, Anne E.,Joullie, Madeleine M.
, p. 4561 - 4564 (2007/10/02)
A novel cyclization reaction is described which affords readily manipulable 3(2H)-dihydrofuranone ethylene ketals, useful in the total synthesis of an ascofuranone model, bullatenone, and muscarine analogs.
