Abstract
The Pyrrolo[2,1-b]thieno[2,3-e][1,3]thiazocinediones (6a,b) resulting from a few known eight membered ring cyclization were successfully described via the Friedel-Crafts cyclodehydration of the appropriates 1-(thien-2′-ylmethyl)-2-pyrrolidinone-5-thioglycolic acids (5a,b).