New approach to the synthesis of dibenzodithia-and benzothiaazacrown ethers via the aromatization of 2-alkylthio(arylthio)cyclohexanes during bromination
The Ugi four-component condensation between 5-oxo-3-thiacarboxylic acids, benzylamines and cyclohexyl isocyanide gave 5-oxothiomorpholine-3-carboxamides. The configuration of bicyclic thiomorpholine derivatives was established by NOESY experiments. (C) 2002 Elsevier Science Ltd. All rights reserved.