Refernces
10.1016/j.tetlet.2006.04.097
The research focuses on the synthesis of substituted 3-furan-2(5H)-ones, which are structural motifs found in numerous bioactive natural products. The methodology involves a Diels–Alder sequence using anthracene and maleic anhydride to form a lactone, which upon deprotonation and electrophilic quenching, yields α-substituted lactones. Key reactants include anthracene, maleic anhydride, sodium borohydride, and various electrophiles such as methyl iodide, allyl iodide, butenyl bromide, benzyl bromide, tributyltin chloride, diethyl chlorophosphate, and chlorotrimethylsilane. The experiments utilize techniques like flash vacuum pyrolysis (FVP) to convert alkylated lactones into 3-substituted furan-2(5H)-ones. The study also explores the challenges and limitations of using cyclopentadiene in such reactions and proposes an alternative route to overcome these issues. Analytical techniques such as 13C NMR and IR spectroscopy were employed to confirm the structure and successful functionalization of the synthesized compounds.
10.1007/s11172-007-0159-0
The study focuses on the development of a new synthetic approach to epoxyisoindolo[2,1-a]quinolines, a class of compounds with potential pharmaceutical interest due to their antihypoxic properties and ability to inhibit human topoisomerase. The synthesis involves cycloaddition reactions of 2-furyl-substituted tetrahydroquinolines with maleic anhydride and acryloyl chloride. Key chemicals used in the study include furfurylideneanilines, alkenes, Lewis acids (such as ZnCl2, ZnI2, SnCl4, TiCl4, AlCl3, or Et2O?BF3), protic acids (like trifluoroacetic, oxalic, or p-toluenesulfonic acid), and activated alkenes. These chemicals serve various roles in the synthesis process, such as catalysts in the Povarov reaction, which is essential for the formation of 2-furyl-substituted tetrahydroquinolines, a precursor in the synthesis of the target epoxyisoindolo[2,1-a]quinolines. The study also explores the influence of the catalyst and solvent nature, as well as the electronic effects of substituents in the aryl moiety of furfurylideneanilines, on the efficiency of the cycloaddition reactions.
10.3987/com-95-7257
The research aimed to develop an efficient synthetic approach to the decalin unit, which is a key intermediate for the synthesis of compactin, a potent competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and an effective hypocholesterolemic agent. The study focused on the microwave-accelerated intramolecular Diels-Alder reaction of substrates 5a-c, which were prepared from 3-ethoxy-2-cyclohexenone. The reaction involved the use of vinylmagnesium bromide, hydrochloric acid, lithium aluminum hydride, ethyl hydrogen malate, ethyl hydrogen fumarate, and BuLi with maleic anhydride. The researchers found that microwave irradiation significantly accelerated the reaction compared to conventional heating, leading to the formation of the desired exo adduct (7c) with high stereoselectivity. The resulting 7c was then converted to the decalin unit (2a) through a series of chemical reactions, thus accomplishing an effective synthesis of the decalin unit required for an approach to compactin.
10.1021/ja01642a044
The study primarily focuses on the synthesis and analysis of various aromatic hydrocarbons and their derivatives. Key chemicals involved include heptaphene, maleic anhydride, dibenzoylphenanthrene, 2,3,8,9-dibenzopicene, and their respective derivatives. Heptaphene was synthesized and characterized by its melting point and solubility properties. Maleic anhydride was used to form an adduct with heptaphene, resulting in the dianhydride (IV). Dibenzoylphenanthrene and 2,3,8,9-dibenzopicene were synthesized through specific reaction sequences involving aluminum chloride and other reagents, and their properties were analyzed. The study also involved the synthesis of 2,3,8,9-dibenzopicene-l,4,7,10-diquinone and its derivatives, exploring their chemical behaviors and properties. The research aims to understand the structural and chemical characteristics of these compounds, contributing to the broader knowledge of aromatic hydrocarbons and their potential applications.
10.1021/jo00387a024
The study explores the ruthenium-catalyzed selective addition of carboxylic acids to alkynes, leading to the novel synthesis of enol esters. The reaction involves carboxylic acids and alkynes as the main reactants, with a catalytic amount of bis(η5-cyclooctadienyl)ruthenium (complex A), a trialkylphosphine ligand (such as PBu3 or PPh3), and maleic anhydride as essential components. The reaction is carried out in toluene at 60-80°C, yielding enol esters with high regioselectivity. The study investigates the effects of various factors, including the type of carboxylic acids, alkynes, phosphine ligands, and solvents, on the reaction's yield and selectivity. It also examines the reaction mechanism through kinetic measurements and the use of deuterated reagents, revealing that the rate has first-order dependence on carboxylic acid, alkyne, and the initial concentration of the ruthenium catalyst. The results show that the phosphine ligands play a crucial role in controlling the regioselectivity of the enol esters, and the presence of maleic anhydride is necessary for the reaction to proceed with saturated carboxylic acids. The study demonstrates the versatility and efficiency of the ruthenium-catalyzed system for the synthesis of enol esters, offering a safer and more selective alternative to traditional methods involving mercury salts.
10.1039/b803926g
This research aimed to synthesize 5-(bromomethylene)furan-2(5H)-ones and 3-(bromomethylene)isobenzofuran-1(3H)-ones, compounds derived from commercially available maleic anhydrides and phthalic anhydrides, with the goal of investigating their potential as inhibitors of microbial quorum sensing (QS), a communication mechanism used by microorganisms to regulate gene expression in response to population density. The study focused on their ability to interfere with microbial communication and biofilm formation by Staphylococcus epidermidis, a bacterium associated with medical implant infections.
10.1134/S1068162018010132
The research aims to synthesize and study a series of new 1,3,4-oxadiazol-2-yl-acrylic acids for their potential antibacterial and protistocidal properties. The study was prompted by the need for new agents against protozoa, which rapidly develop resistance to existing drugs, and the recognition that compounds bearing an acrylic acid residue and a heterocyclic fragment could exhibit enhanced biological activity. Key chemicals used in the synthesis include maleic anhydride, various hydrazides, and POCl3. The synthesized compounds were tested for their biological activity against Staphylococcus aureus, Escherichia coli, and the protozoa Colpoda steinii. The results showed that p-substituted benzyl derivatives in the Z-form exhibited high protistocidal activity, surpassing the reference drug Baycox (toltrazuril) by several times. Notably, the 3-hydroxy-2-naphthyl derivative (IVj) demonstrated both very high protistocidal activity and moderate antibacterial activity. The study concludes that the search for antiprotozoal compounds within this class, especially Z-isomers, is promising, and these derivatives could serve as a basis for developing new pharmaceuticals with improved efficacy against both bacterial and protozoal infections.
C
