Design and Preparation of New Chiral Ligands for Stereoselective Synthesis of certain Monobactams

The sumitted dissertation is prefaced by a comperhensive literature survey on the asymmetric synthesis , the importance of the use of optically pure compounds in relation to their pharmacological activities, the general methods that can be used for asymmetric synthesis. Moreover, it comprises asurvey about the biological activities and the general methods for the synthesis of optically active B-lactam derivatives. the results obtained using type 1 ligands (1-3) showed no significant differences in enhancement of the enantioselctivity under any experimental conditions (I-III). however, the type 2 amines (4,6 and 7) showed comparable differences of such parameter. the first seven new chiral ligands (1-7) are of the (1R,2R)- configuration and the monobactam LXXXV, obtained by their use, is almost in variable ee% of its (S)-configuration . this is consistent with the published data for the like (1R,2R)-1,2-diphenylethane derivatives . meanwhile, the only case resulting in such a high ee% (74%) for the (R)-antipode of compound LXXXV is that of ligand 8, which is evidently of the (1S, 2S)-configuration. this might open the door for enantioselective synthesis of compound LXXXV (-R)using other (1S,2S)-ligands pf the diphenylethane series.