The synthesis and acid-catalysed rearrangements of 4-hydroxycyclohexa-2,5-dienones

Abstract

Bicyclic unsaturated ketones possessing an angular hydroxy-group are dehydrogenated with 2,3-dichloro-5,6-dicyanobenzoquinone to the corresponding hydroxydienone (p-quinol) this providing a new route to these systems. The boron trifluoride-catalysed rearrangement of a p-quinol has yielded a spiro-diketone, providing the first example of the isolation of a spiran from the acid-catalysed rearrangement of a bicyclic dienone.