Synthesis of 5-Methylene-1,3-oxazolidin-2-ones
The interesting activity of the latter group has triggered the synthesis of several of these compounds and their analogues.
Application in the Synthesis of Ligands for Asymmetric Catalysis
Dayse das Neves Moreira was born in Canguçu, Rio Grande do Sul state, Brazil, in 1984. She received her undergraduate degree in Chemistry from the Federal University of Pelotas, RS, in 2006, and in 2008, she received her M.S. degree from the Federal University of Santa Maria, RS, Brazil, working under the direction of Prof. Dr. Marcos A. P. Martins. Currently, she is a Ph.D. student with Prof. Dr. Marcos A. P. Martins in the Department of Chemistry of the Federal University of Santa Maria. Her major research interest is to develop new methodologies to synthesize heterocyclic compounds.
Aryl iodides are essential building blocks for the synthesis of functional molecules, and efficient methods for their synthesis from ...
Part 1: The Synthesis of (S)-2-Methylhexanoic Acid
This transient intermediate undergoes a subsequent intramolecular Diels-Aldercycloaddition across the tethered ¼-bond to furnish cycloadduct51. Nitrogen-assisted ring opening of the oxabicyclic bridge resultsin the formation of zwitterionic intermediate 52 which undergoesa 1,2-thioethyl shift followed by methoxide ion ejection. Cyclization ofthe diactivated aromatic tether onto -acyliminium ion 54 ultimatelyprovides the tetracyclic amide 55. With a supply of 55 inhand, this enone was converted into the corresponding vinyl triflate which,in turn, was subjected to a palladium catalyzed formate reduction to give56. The resulting thio-substituted diene was subsequently transformedinto ketone 57 a titanium mediated hydrolysis. The presentsequence constitutes a formal synthesis of (±)-erysotramidine (58)based on the successful conversion of 57 into 58 by Tsudaand coworkers (Scheme 11) .
At this point, we decided to undertake a synthesis of (±)-erysotraamidine(58) in order to further test the viability of the triple cascadeprocess as an entry into the erythrinane skeleton. The requisite startingimidosulfoxide 49, possessing both a dienophilic and diactivatedaromatic ¼-tether, was efficiently synthesized from known startingmaterials. Subjection of 49 to the Pummerer conditions gave compound55 as a single diastereomer in 83% yield. The A/B ringfusion present in 55 was unequivocally established by an X-ray crystallographicanalysis and is identical to the stereochemical relationship found in thenaturally occurring Erythrina alkaloids. The conversion of 49 into55 is believed to follow the pathway outlined below (Scheme 10).The initially formed alpha-thiocarbocation intermediate generated fromthe Pummerer reaction of 49 is intercepted by the adjacent imidocarbonyl to producethe alpha-amido substituted furan 50.
New Synthesis of Chiral Oxazolidin-2-ones
Our database will be updated periodically. A next update version is planned for summer 2013. Up to 50,000 new structures including their physical and chemical properties and synthesis references will be available. To learn more about this project please go to the page.
A short synthesis of 27 and 28 was carried out as depictedin Scheme 7. This approach is centered on the construction of the key dihydroindoles33 and 34 which are formed by a cycloadditionfollowed by subsequent nitrogen atom lone pair assisted ring opening ofthe initially formed oxabridged cycloadducts. After some experimentation,it was found that using (tributyltin) under photochemical conditionsafforded the aryl-coupled products 35 and 36 in high yieldfrom the corresponding dihydroindoles 33 and 34. Both compoundswere converted to the natural products by a saponification-decarboxylationprotocol.
synthesis, reactions, and application
Total synthesis of (+)-16-epivinoxine and (−)-vinoxine
Highly Regio- and Stereoselective Synthesis of 2-Amino-3-alken-1-ols or 4-Amino-2(E)-alken-1-ols
A key step for a (−)-norephedrine synthesis
Application to the Synthesis of Various Enantiomerically Pure Compounds
Dev Synthesis – Making Chemistry Simple
A Synthesis of d-Sabinene
A Custom Synthesis Company - Capot Chemical
Heterocyclic compounds are of very much interest in our daily life. Heterocyclic compounds have one or more hetero atoms in their structure. They may be cyclic or non cyclic in nature. Heterocyclic compunds have a wide range of application. They are predominantly used as pharmaceuticals, as agrochemicals and as veterinary products. They also find applications as sanitizers, developers, antioxidants, as corrosion inhibitors, as copolymers, dye stuff. They are used as vehicles in the synthesis of other organic compunds. Some of the natural products e.g. antibiotics such as penicillin’s, cephalosporin; alkaloids such as vinblastine, morphine, reserpine etc. have heterocyclic moiety.
Synthesis of Heterocyclic Homotriptycenes - The …
A series of novel heterocyclic homotriptycenes bearing furan, thiophene, and pyridine rings, 7a–f, were synthesized by intramolecular dehydration reactions of 10,10-dihetarylmethyl-9,10-dihydroanthracen-9-ols 6a–f. In the presence of acids, the secondary alcohols 6a–f show different reactions which depend on the electron densities of the attached heterocyclic rings. The initially formed carbenium ions react in an electrophilic substitution with electron-rich heterocycles. The formation of a transannular bridge (1,7-elimination) leads to homotriptycenes in high yields. When the heterocyclic ring has a moderate electron density, two competitive reactions exist, which afford 9-monosubstituted anthracenes by 1,4-elimination or 9,10-disubstituted anthracenes by a rearrangement, respectively. Electron-deficient heterocycles undergo a disproportionation to give hydrocarbons and ketones.
Synthesis of Heterocycles - Chemistry
Pyridine and pyrrole are both nitrogen heterocycles-their molecules contain nitrogen atoms along with carbon atoms in the rings. The molecules of many biological materials consist in part of pyridine and pyrrole rings, and such materials yield small amounts of pyridine and pyrrole upon strong heating. In fact, both of these substances were discovered in the 1850s in an oily mixture formed by strong heating of bones. Today, pyridine and pyrrole are prepared by synthetic reactions.
Efficient Synthesis of Heterocycles via ..
ChemSynthesis is a freely accessible database of chemicals. This website contains substances with their synthesis references and physical properties such as melting point, boiling point and density. There are currently more than 40,000 compounds and more than 45,000 synthesis references in the database.
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