On the Intramolecular 1, 4-Dipolar Cycloaddition Reaction of Thiazinium Betaines for the Construction of Aza-, Diaza-, and Polyaza-Heterocyclic Ring Systems
1a 1b 1c not readily accessible by cyclocondensation routes. The overall convenience of this method, the ease of access to starting materials, and the relatively high yields and pu- rity of the products obtained suggested its application to the preparation of a number of polycyclic ring systems of interest in natural product chemistry. This paper esta-blishes the synthetic utility of the intramolecular 1, 4-di-polar cycloaddition of a series of conjugated ...
