Synthesis of 2-O-heteroaroyl taxanes: evaluation of microtubule assembly promotion and cytotoxicity

A series of heterocyclic taxanes were synthesized and evaluated to investigate structure activity relationships at the 2-position of paclitaxel. The compounds were prepared through a regioselective deacylation, reacylation sequence of suitably protected paclitaxel. The heterocyclic substituted diterpenes were synthesized from paclitaxel in four steps in high overall yields. Evaluation of these analogues in a microtubule assembly assay and for their cytotoxicity against B16 melanoma cells illustrated that these compounds had diminished activity compared to paclitaxel