Rearrangement of 2-phenoxyvinyl ketones

Abstract

1. It has been shown that in the reaction of 2-phenoxy- and 2-(2-naphthyloxt)-vinyl ketones with ferric chloride in a mixture of acetic and concentrated hydrochloric acids, a rearrangement associated with the migration of the 3-oxo-1-alkenyl group to the ortho- and para-positions in the aromatic nucleus takes place. 2. 2-(2-Naphthyloxy)- and 2-phenoxy-vinyl ketones having u para-subs tituent in the aromatic nucleus giveα-substituted naphtho- and benzo-pyrylium salts when treated with ferric chloride. 3. 2-Phenoxyvinyl ketones having no para-substituent in the aromatic nucleus give mixtures of the benzopyrylium salt and the alkyl 2,2-bis(p-hydroxyphenyl)ethyl ketone when treated with ferric chloride. 4. It has been shown that zinc chloride in hydrochloric acid also promotes the rearrangement of phenoxyvinyl ketones, resulting in the formation of only alkyl 2,2-bis(p-hydroxyphenyl) ethyl ketones. 5. It has been shown that, in presence of zinc chloride, 4-(p-methoxyphenyl)-3-buten-2-one unites at its double bond with a molecule of phenol.