ChemInform Abstract: Cycloaddition of Pyridinium Methylides with Electron-Deficient Olefins and Silica-Gel Mediated Elimination of Pyridines from the Cycloadducts: A New Method of Alkylation or Hydroalkylidenation of Olefins.

ChemInform Abstract

The pyridinium methylides derived from base treatment of (I) react with a variety of olefins such as (II), (V) or (VII) to form cycloadducts (for example (III)), which undergo ready elimination of pyridines to give the alkylated or hydroalkylidenated products (IV), (VI) (mixtures of isomers and/or tautomers) or (VIII) (yields of (III), (VI) and (VIII) are based on (II), (V) and (VII)).