Aziridine intermediates, synthesis of natural products via

Natural products, synthesis via aziridine intermediates, 39, 181 New developments in the chemistry of oxazolones, 21, 175 Nitration of phenyl-substituted heterocycles, 58, 215 Nitrenes, carbenes and, intramolecular reactions of, 28, 231... 

Mechanistic approaches to asymmetric aziridine synthesis have been carried out systematically using a variety of p-substituted benzaldehydes (Table 4.16). Two kinds of reaction mechanism, controlled by the nature of the p-substituent of aryl aldehydes, are proposed an S i-like mechanism, via cationic-like transition state for the fragmentation of intermediate adducts to aziridine products (step 2) by intramolecular nucleophihc substitution, when EDG-substituted benzaldehydes are used and an Sielectron-withdrawing group (EWG) substituted benzaldehydes are used [99]. 

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