Bazı münknon türevlerinin elektonca eksik alkenlerle reaksiyonları

This thesis general describes a variety of reactions of 1,3-oxazolium-5-oxides, commonly known as Münchnones which are a special class of azomethine ylides with electron-deficient dipolarophilic reagents. In this regard, a series of pyrroles, N-benzoyl benzamides, p-substituted benzoic acids and N-acyl ureas have been obtained. These compounds are important heterocycles, widely present in natural and many pharmaceutical compounds. There are many synthetic methods to prepare pyrrole derivatives in the literature. Among them, 1,3-dipolar cycloaddition reaction of Münchnones with alkynes and alkenes are versatile. The purpose of this dissertation is to study the reactions of mesoionic Münchnone derivatives with electron deficient alkenes. The outcomes of these compounds were discussed in three parts; In the first part, the cycloaddition reaction of in situ generated Münchnones from N-acyl amino acids with benzo[b]thiophene 1,1-dioxide is described. The accompanying deoxygenation of sulfone moiety gave rise to the benzothiophene fused pyrrole derivatives. In order to rationalize the entire reaction, the transformation of sulfide into sulfone group which is the anticipated product was carried out by means of m-chloroperbenzoic acid oxidation. The second part of this work was involved in the synthesis of (E)-1-(N,4-dimethylbenzamido)-1-(4-fluorophenyl)prop-1-en-2-yl acetate, 4-aryl-N-methyl-N-(4-substitutedbenzoyl)benzamides and p-substituted benzoic acids by the reaction of in situ generated Münchnones from 2-(4-substitutedphenyl)-2-(N-methyl-N-p-substitutedbenzamido)acetic acids with acetic anhydride in the presence of 2-nitromethylene thiazolidine. A plausible Dakin-West type mechanisms for these reactions were proposed. The last part of this thesis, a novel efficient route leading to N-acyl urea derivatives was described by the reaction between Münchnone precursors with carbodiimides in the presence of a base.