Enchainements heteroatomiques et leurs produits de cyclisation—I

2-Aminovinyl thioketones react with α-bromoketones, ketenes and sulfenes to give respectively substituted 2-acylthiophens, thiopyran(2H)-2-ones, 5,6-dihydro-1,2-dithiin-1,1-dioxides and 1,2-dithiin-1,1-dioxides by a cycloaddition process in good agreement with predictions based on calculated interactions between 2-aminovinyl thioketones and ketenes.