NOVEL FORMATION OF 4-METHYLTHIOPYRENE IN A HOFMANN ELIMINATION-REACTION DIRECTED TOWARD THE SYNTHESIS OF 17,19-DIOXA[2.2.3](1,2,3)CYCLOPHANEDIENE

The synthesis of 17,19-dioxa[2.2.3](1,2,3)cyclophanediene was attempted via a Stevens rearrangement-Hofmann elimination sequence on 1 9,21-dioxa-2,11-dithia[3.3.3] (1,2,3)cyclophane. Pyrene and 4-methylthiopyrene were, however, the isolated products. The structure of the latter was fully characterized by UV, MS, 1D and 2D H-1 NMR spectra. Formation of 4-methylthiopyrene was expected to involve a novel base-induced ring cyclization resulting in elimination of methanoate anion from the methylenedioxy bridge followed by a novel 1,4-hydride shift resulting in the elimination of methane.