2,2'-Biphenol- and (R/S)- and (R)-1,1'-bi(2-naphthol)-based polysulfones were synthesized by classical step-growth polymerizations and by entropically-driven ring-opening polymerizations (ED-ROPs) of the corresponding macrocyclic oligomers (MCOs). To facilitate comparisons, the polysulfone derived from 4,4'-cyclohexylidenebisphenol was synthesized similarly. ED-ROP was also used to prepare copolymers. The molecular weights obtained using ED-ROP were generally higher than those obtained using the classical step growth method. The MCOs required as the starting materials for ED-ROPs were prepared by classical high dilution syntheses using the biphenols and bis(4-chlorophenyl)sulfone in the presence of base. The cyclic dimer from a high dilution synthesis using (R)-1,1'-bi-2-naphthol and the cyclic dimer from a similar synthesis using 4,4'-cyclohexylidenebisphenol were isolated as pure compounds by column chromatography and the molecular structures determined by single crystal X-ray diffraction. Copyright (c) 2006 John Wiley & Sons, Ltd.