Alkyl benzyl ketoximes react with acetylene at 60-150 °C in MOH-dimethyl sulfoxide (M = Li, K) primarily by means of the methylene group of the benzyl grouping, which is primarily anti-oriented with respect to the hydroxy group, to give 2-alkyl-3-phenylpyrroles in greater than 70% yields. The specific participation of the antimethylene group in the construction of a pyrrole ring constitutes evidence against mechanisms that include a [3,3]-sigmatropic shift in O-vinyl oximes. It follows from the results obtained that the reaction proceeds through an anti-dianion of the benzyl type stabilized by conjugation with the aromatic ring.
|Number of pages||5|
|Journal||Chemistry of Heterocyclic Compounds|
|State||Published - 1 Feb 1982|
ASJC Scopus subject areas
- Organic Chemistry