Constituents of commercial methoxychlor-III. The mechanism of tetraanisylethylene formation. unsym-Tetraarylethylenes (Ar2C=CAr2′): synthesis from DT class pesticides, and conversion to phenanthrenes and dibenzo[g,p]chrysenes

Abstract

Reaction of DT type pesticides with anisoie and A1Cl3 in CS2 yielded unsym-tetraarylethylenes (Ar2C=Ar2′), which on photocyclisation yielded phenanthrenes. Further oxidative closure to dibenzo[g,p]chrysenes occurs under conditions that faveur cation radical intermediates. Chromatography of commercial methoxychlor (DMDT) yielded tetraanisylethylene together with minor amounts of the corresponding photo products, 3,6-dimethoxy-9,10-dianisylphenanthrene and 3,6,11,14-tetramethoxydibenzo[g,p]chrysene, as well as other chloroanisylethylenes.