A simple approach to the synthesis of highly functionalized 3-alkylidene-2,3-dihydro-1H-pyrrole-2-ol derivatives and related pyrroles.

The reaction of various primary amines with acetylenic esters at ambient temperature in THF/H(2)O (50:50) produced related enaminones. Subsequently reaction of these in situ prepared enaminones with dibenzoylacetylene leads to 3-alkylidene-2,3-dihydro-1H-pyrrol-2-ol derivatives in good yields. The reaction of these products with various alcohols in the presence of a catalytic amount of HCl produced highly functionalized pyrroles in nearly quantitative yields.