Synthesis of Fluorinated Derivatives of Benzofluoranthene and Indenopyrene and 8,9-dihydro-8,9-epoxybenzofluoranthene

Article abstract of DOI:10.1021/jo00243a032

The synthesis of several select fluorinated derivatives of benzofluoranthene and indeno<1,2,3-cd>pyrene is described.In the benzofluoranthene series, the 8- and 9-fluoro derivatives have been prepared by Wittig reaction of the 1,2-bis<(triphenylphosphonio)methyl> salt of the appropriate fluorobenzene with acenaphthenequinone under phase-transfer conditions.The synthesis of 2-fluoroindeno<1,2,3-cd>pyrene was achieved by photocyclization of 1-(β,β-difluorovinyl)benzofluoranthene followed by dehydrofluorination in methanolic sodium methoxide.This represents a new method for the construction of the indeno<1,2,3-cd>pyrene skeleton. 8,9-Difluoroindeno<1,2,3-cd>pyrene was prepared from 1-(2-amino-4,5-diflurophenyl)pyrene by diazotization followed by coupling in the presence of copper-bronze.In addition to these fluorinated derivatives, the synthesis of 8,9-dihydro-8,9-epoxybenzofluoranthene, a suspect ultimate tumorigenic metabolite of benzofluoranthene, is reported.This arene oxide was prepared from the trans-8,9-bromo acetate by benzylic bromination and subsequent treatment with sodium methoxide in anhydrous THF.