Synthesis of Aminoalkylated Aziridines from (+)-3-Carene

Aminoalkylated carane-type aziridines were synthesized via epoxidation of (+)-3-carene by H2O2 solution (7%) in EtOAc catalyzed by α-Al2O3 nanoparticles, opening of the epoxide by NaN3, and cyclization of the azidoalcohol by Ph3P followed by condensation of the resulting aziridines with formalin and secondary amines. The cytotoxicity of the aminoalkylated aziridines with heteroorganic substituents increased on going from a five-membered pyrrolidine ring substituent to a six-membered piperidine ring and decreased sharply upon replacing a piperidine by a morpholine ring or increased on going to a piperazine ring. The structures of products were established using IR and NMR spectroscopy and an X-ray crystal structure analysis.