Selective alkylation: a biomimetic reaction of the antileukemic triptolides?

The potent antileukemic plant principles triptolide and tripdiolide contain a characteristic hydrogen-bonded 9,11-epoxy-14beta-hydroxy system. They alkylate propanethiol in a process which involves opening of the epoxide function with neighboring hydroxyl assistance. The reaction may mimic the inhibition of tumor growth via selective alkylation of the thiol groups of key enzymes concerned with groth regulation.