1,5-Hydride shifts in acyclic systems containing αβ-unsaturated ketones and p-methoxyphenyl groups

Abstract

Acid-catalysed rearrangement of 8-(p-hydroxyphenyl)oct-3-en-2-one (4) to [2-(p-hydroxyphenyl)cyclohexyl] methyl ketone (10) is shown to involve an intramolecular hydride shift by deuterium labelling: a similar rearrangement is observed for 8-(p-hydroxyphenyl)-5,5-dimethyloct-3-en-2-one (3) and its aromatic methyl ether (2) but no analogous products could be isolated from 7-(p-methoxyphenyl)hept-3-en-2-one (18) or 7,7-bis-(p-methoxyphenyl)hept-3-en-2-one (19) under the same reaction conditions.