856680-13-2Relevant academic research and scientific papers
Ring-closure reactions through intramolecular substitution of thiophenoxide by oxygen and nitrogen nucleophiles: Simple stereospecific synthesis of 4,5-dihydroisoxazoles and 4,5-dihydropyrazoles
Zielinska-B?ajet, Mariola,Kowalczyk, Rafa?,Skarzewski, Jacek
, p. 5235 - 5240 (2007/10/03)
A new and simple method for the stereospecific synthesis of 3,5-disubstituted-4,5-dihydro-isoxazoles (chiral isoxazolines) from readily available oximes of chiral Michael adducts of thiophenol to chalcones is reported. An analogous reaction with the N-arylhydrazones of the Michael adduct gave nonracemic 1-(aryl)-3,5-diphenyl-4,5-dihydro-1H-pyrazoles (chiral pyrazolines), but these products are configurationally unstable. The key step of the synthesis is the ring-closure reaction, which occurs by a stereospecific intramoleculer nucleophilic substitution of thiophenoxide.
