A facile access to novel steroidal 17-2'-(1',3',4')-oxadiazoles, and an evaluation of their cytotoxic activities in vitro.

Novel types of 17-exo-heterocycles in the Δ(5) androstene series carrying an 1,3,4-oxadiazole moiety were efficiently synthesized via aldehyde N-acylhydrazone intermediates, obtained from the microwave-assisted condensation of 3β-hydroxy- or 3β-acetoxyandrost-5-ene-17β-carbaldehyde with different acylhydrazides. The subsequent phenyl iodonium diacetate-induced oxidative cyclization proceeded under mild conditions. The synthesized compounds were subjected to in vitro pharmacological studies to investigate their antiproliferative activities on four malignant adherent cell lines (HeLa, MCF7, A2780 and A431), and exhibited the highest potency against HeLa cells, some of them revealing action comparable to that of the reference agent cisplatin.