Semi-synthesis of 1-deoxypaclitaxel and its analogues from 1-deoxybaccatin VI.

Despite numerous synthetic efforts and extensive SAR studies on paclitaxel analogs, little work has been devoted to derive SAR of the C-1 hydroxy group. Up to now, 1-deoxypaclitaxel has only been reported to be isolated from the Chinese yew, Taxus mairei (Taxaceae). However, the isolation from natural sources does not solve the availability problem due to the reported low yield of isolation. Also, only several analogues of this type have been reported. Thus, there is an urgent need for exploration of new synthetic methods on this structurally intriguing molecule and further SAR studies. In present work, we report the initial expedient semi-synthesis of 1-deoxypaclitaxel and its novel analogues with structural variations at C7 and C10 from 1-deoxybaccatin VI, as well as their cytotoxic activities against A 549 cell line.