Synthesis of Bisphenol Z: An Organic Chemistry Experiment

A student achievable synthesis of bisphenol Z, 4,4′-(cyclohexane-1,1-diyl)diphenol, from the acid-catalyzed reaction of phenol with cyclohexanone is presented. The experiment exemplifies all the usual pedagogy for the standard topic of electrophilic aromatic substitution present in the undergraduate organic chemistry curriculum, while providing the opportunity to create a product that is a member of a family of compounds (including bisphenol A) that is industrially important, but with significant controversy over health and environmental concerns. The synthesis can serve as a springboard for discussion or research on a variety of related topics such as polymer plastic or epoxy resin synthesis, intellectual property and patents, endocrine system disruptors, and environmental toxicology. The experiment has a very low cost of ownership, is reliable at producing yields of 45%, and may be completed in a single laboratory period. In addition, it serves as an example of a reaction that forms an isolable stoichiometric adduct between the product and unreacted reagent (phenol) and is readily differentiated and characterized by melting point, thin-layer chromatography, and 1H NMR.