Chemistry of Organo Halogenic Molecules. XLVIII. Stereochemistry of Halofluorination of 1,2- and 1,4-Dihydronaphthalene

Abstract

Abstract Halofluorination of 1,2-dihydronaphthalene with a mixture of N-chlorosuccinimide or N-bromosuccinimide or N-iodosuccinimide–hydrogen fluoride–pyridine in ether proceeds with Markovnikov type regioselectivity. The reaction is stereospecifically anti, the anti adduct isomerizing to syn products under the reaction conditions. The elimination of hydrogen halide under basic conditions occurs only from the syn adduct, thus forming 1-fluoro-3,4-dihydronaphthalene. Halofluorinations of 1,4-dihydronaphthalene also occur stereospecifically anti, and elimination under basic conditions gives naphthalene.