MODERN FRIEDEL-CRAFTS CHEMISTRY.XI. CYCLIZATION OF ARYL HALOALKYL SULFONES, ARYLSULFONYLACYL CHLORIDES AND THEIR CORRESPONDING SULFIDES

Abstract

The sulfone group deactivation for cyclialkylation and cycliacylation reactions in the presence of Friedel-Crafts catalysts was demonstrated in a number of aryl chlorlalkylsulfones (1–8) and arylsulfonylacyl chlorides (17a-22a), respectively. As expected, the corresponding arylchloralkyl sulfides (9–16) and arylmercaptoacyl chlorides (13a-28a) underwent ring-closure reaction in most cases under the same conditions. The ease of cyclization was governed by the ring size, the stability of the attacking carbocation and the nucleophilicity of the aryl moiety. Also the behaviour of benzyl sulfones (29, 31a, and 32a) and sulfides (33, and 36a) was inconsistent. Noteworthy, the Friedel-Crafts cyclization reaction is thus considered an accessible method for the synthesis of compound 37–41 and 45,51.