Formaldehyde condensations with phenol and its homologues. XVI. The trinuclear novolaks

Each of the seven isomeric trinuclear novolaks that may be formed during the condensation of phenol and formaldehyde has been synthesized by at least two independent routes. These compounds may be formed, during resin formation, from oo′‐, op′‐ and pp′‐dihydroxydiphenylmethanes by treatment first with formaldehyde to yield the dinuclear alcohols,1 and subsequently with phenol. The compounds synthesized are crystalline solids, contrary to a previous report that some of them are resinous2.