Isomerization of bisphenols

In the process for isomerization of bisphenols in the presence of phenols and catalyst, the improvement comprises contacting a bisphenol of the formula ##STR6## with a phenol of the formula ##STR7## and a catalyst selected from the group consisting of protonic acids, Lewis acids and acid ion exchange resins,

• wherein
• R.sup.1 to R.sup.8 are the same or different and each is, independent of the others, hydrogen or alkyl having 1-12 carbon atoms,
• X is alkylidene having 1-12 carbon atoms or cycloalkylidene having 3-12 carbon atoms, with X in the ortho or para position to the --OH,
• R.sup.11 to R.sup.14 are the same or different and each is, independent of the others, alkyl having 1-12 carbon atoms, halogen, aryl having 6-24 carbon atoms, alkoxy having 1-12 carbons atoms or cycloalkyl having 5-30 carbon atoms.