Pyridinium ylids in synthesis. III. Synthesis of indolizines

Abstract

Treatment of pyridinium, quinolinium, and isoquinolinium ylids with acetylenes yields indolizine derivatives. Pyridinium phenacylid with iodine in dimethylacetamide gives 1,2,3-tribenzoylindolizine. Decomposition of pyridinium phenacylid in the presence of copper or copper oxide affords 1,3-dibenzoylindolizine.