Synthesis of 1,2,3,5-Tetrasubstituted Pyrrole Derivatives from 2-(2-Bromoallyl)-1,3-dicarbonyl Compounds.

2-(2-Bromoallyl)-1,3-dicarbonyl compounds are converted into β-enamino, β-hydrazino esters and ketones, followed by base-promoted cyclization, leading to the formation of the corresponding 1,2,3,5-tetrasubstituted pyrroles. 1,2,4- and 1,2,3,4-Substituted pyrroles are also isolated as minor products. Starting from the 2-(2-bromoallyl)-cyclohexane-1,3-dione the corresponding tetrahydro indolone is prepared in good yield.