Properties and Reactions of 4-Thioxo-2-azetidinones

Article abstract of DOI:10.1021/jo01296a027

4-Thioxo-2-azetidinones represented by compounds 1-4 appear to be suitable substrates for contrasting the chemistry of the C=O ans C=S linkages.Hydrolysis and alcoholysis occur selectively at the carbonyl bond while 1,3-dipolar reagents like diazoalkanes and ozone, as well as carbenes, attack exclusively at the thiocarbonyl function.The 4-alkylidene-2-azetidinones 35-38 have been obtained from the 4-thioxo-2-azetidinones 3 or 4 and 2-diazopropane, diphenyldiazomethane, or ethyl diazomalonate.The reactions with 2-diazopropane involved the formation of thiadiazolines from which the sulfur and nitrogen elements were extruded.The rections with the last two reagents which were performed in the presence of Rh(OAc)2 involved carbene intermediates.