Microwave-assisted synthesis of calix[4]resorcinarenes

Abstract Microwave-assisted synthesis of calix[4]resorcinarenes by cyclocondensation of various aldehydes and resorcinol catalysed by 12-tungstophosphoric acid type Keggin (H 3 PW 12 O 40 ·13H 2 O) or concentrated HCl is described. Excellent isolated yields (up to 90%) were attained within short reaction times (typically, 3–5 min) when the reaction was performed under microwaves irradiation.