ABSTRACT
The present work aimed to synthesise promising antioxidant compounds as a valuable alternative to the currently expensive and easily degradable molecules that are employed as stabilizers in industrial preparation. Taking into account our experience concerning domino Friedel-Crafts/lactonization reactions, we successfully improved and extended the previously reported methodology toward the synthesis of 3,3-disubstituted-3H-benzofuran-2-one derivatives 9-20 starting from polyphenols 1-6 as substrates and either diethylketomalonate (7) or 3,3,3-trifluoromethyl pyruvate (8) as electrophilic counterpart. The antioxidant capacity of the most stable compounds (9-11 and 15-20) was evaluated by both DPPH assay and Cyclic Voltammetry analyses performed in alcoholic media (methanol) as well as in aprotic solvent (acetonitrile). By comparing the recorded experimental data, a remarkable activity can be attributed to few of the tested lactones.
Subject(s)
Antioxidants/pharmacology , Benzofurans/chemical synthesis , Benzofurans/pharmacology , Biphenyl Compounds/chemistry , Electrochemistry/methods , Picrates/chemistry , Acetonitriles/chemistry , Alkylation , Antioxidants/chemistry , Kinetics , Methanol/chemistry , Oxidation-Reduction , Phenols/chemistry , Phenols/pharmacology , Regression Analysis , SolventsABSTRACT
In the present work, we report the synthesis of the novel esters of indomethacin (IDMC) and an ester of reduced IDMC. For this purpose, IDMC is covalently bound by using a spacer chain to the pyrrole (Py) in the 3-position. The innovative pyrrole-indomethacin (3-Py-IDMC) derivates show no cytotoxic effects in primary calvarial osteoblasts. The designed IDMC derivates have been studied because they could be injected locally as a component of polymeric micro-particles. In fact, the new 3-Py-IDMC derivatives will assure their further polymerization since the 2- and 5-monomer positions are free.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Delayed-Action Preparations/chemical synthesis , Indomethacin/chemistry , Pyrroles/chemistry , Actins/chemistry , Animals , Animals, Newborn , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Cell Proliferation/drug effects , Cell Survival/drug effects , Delayed-Action Preparations/pharmacology , Esters , Histocytochemistry , Injections, Intra-Articular , Male , Mice , Osteoblasts/cytology , Osteoblasts/drug effects , Oxidation-Reduction , Primary Cell Culture , Rats , Rats, Sprague-Dawley , Skull/cytology , Skull/drug effectsABSTRACT
A novel asymmetric nucleophilic epoxidation for α-ylideneoxindole esters has been successfully devised, resulting in enantioenriched spiro compounds with two new contiguous stereocenters. The employed (S)-α,α-diphenylprolinol functions as a bifunctional catalyst, creating a complex H-bond network in conjunction with a substrate and an oxidant.
Subject(s)
Epoxy Compounds/chemical synthesis , Indoles/chemistry , Indoles/chemical synthesis , Spiro Compounds/chemical synthesis , Catalysis , Epoxy Compounds/chemistry , Esters , Molecular Structure , Spiro Compounds/chemistry , StereoisomerismABSTRACT
Beta-Ketoallylsilanes are synthesized by the Horner-Emmons reaction starting from novel silylated ketophosphonates and various aldehydes. The reactions of beta-ketoallylsilanes with NsONHCO2Et and CaO produce alpha-methylene-N-(ethoxycarbonyl)-beta-amino ketones through the ring opening of the intermediate aziridine, which is favored by the presence of the trimethylsilyl group. With chiral beta-ketoallylsilanes we obtained a stereoselective amination reaction with a 90% diastereomeric excess. alpha-Methylene-N-(ethoxycarbonyl)-beta-amino ketones are isolated in 39-60% yields and characterized.
Subject(s)
Alkenes/chemistry , Ketones/chemical synthesis , Silanes/chemistryABSTRACT
We have discovered that alpha-[dimethyl(thexyl)silyl]acetaldehyde (= [dimethyl(1,1,2-trimethylpropyl)silyl]acetaldehyde; 31) has a strong, woody odor. Structural analysis has shown resemblance to known odorants with similar organoleptic properties. On the basis of structure-odor relationships, new and more-powerful woody and ambery sila odorants were prepared. Further derivatization led to a set of compounds with very interesting organoleptic properties. Selected chiral compounds were also prepared stereoselectively. The influence of the absolute configuration on the olfactory properties was in agreement with theoretical assumptions. We also designed other groups of organosilicon odorants. The compounds discovered can be obtained in a few simple steps from commercially available reagents, and may find application in the fragrance and flavor industry. Their structures provide interesting data for further research on structure-odor relationships.
