Axially chiral N-(o-aryl)-2-thioxo-oxazolidine-4-one and rhodanine derivatives: enantiomeric separation and determination of racemization barriers

Abstract

Bu çalışmada sterik engelli 5,5-dimetil-3-(o-aril)-2-tiokso-4-oksazolidinon, 5,5-dimetil-3-(o-aril)-2-tiokso-4-tiazolidinon(rodanin) ve 3-(o-aril)-2-tiokso-4-tiazolidinon(rodanin) türevleri rasemik olarak arilisotiosiyanatların 2-hidroksiisobütratlarla ya da arilisotiosiyanatların tioglikolikasit etilesterle olan reaksiyonlarından sentezlenmişlerdir. 5,5-dimetil-rodaninler modifiye Kaluza metoduna göre sentezlenmişlerdir. Bileşiklerin kiraliteleri, heterosiklik halkanın C-5 posizyonundaki metil ve metilen protonlarının varlığında 1H ve 13NMR spektroskopisi ile ispatlanmıştır.

In this study, sterically hindered 5,5-dimethyl-3-(o-aryl)-2-thioxo-4-oxazolidinones, 5,5-dimethyl-3-(o-aryl)-2-thioxo-4-thiazolidinones and 3-(o-aryl)-2-thioxo-4-thiazolidinones(rhodanines) have been synthesized as racemates by either the reaction of o-aryl isothiocyanates with ?-hydroxyisobutyrate or by treatment of o-arylisothiocyanates with the correponding thioglycolic acid ethyl ester. The 5,5-dimethylrhodanines have been synthesized according to Modified Kaluza synthesis. Chirality of the compounds has been proven by the presence of diastereotopic methylene protons or methyl groups on C-5 of the heterocyclic ring detected by 1H NMR or 13C NMR spectroscopy.