2,2-Dichlorocyclobutanones reacted with various amines to give ring opening leading to 4,4-dichlorobutanamides. These compounds proved to be suitable substrates for the synthesis of 3-pyrrolin-2-ones, 2-pyrrolidinones, pyrrolidines and pyrroles.
cyclobutanones - ring opening - ring expansion - pyrroles - heterocycles