Acyclic p-cresol-formaldehyde oligomers (dimer, trimer, and tetramer) having ester, carboxylic acid, amide groups on the phenolic OH groups were prepared in good yields. ... Acyclic p-cresol-formaldehyde oligomers (dimer, trimer, and tetramer) having ester, carboxylic acid, amide groups on the phenolic OH groups were prepared in good yields. ... Calixarenes are cyclic phenol–formaldehyde condensation products, which are extensively investigated as host ...