Site-Selective Functionalization of Unactivated Allylic C-H Bonds via Direct Deprotonation with KTMP: Application to the Formal Total Synthesis of (+)-Artemisinin from Amorphadiene.

The site-selective functionalization of unactivated allylic C-H bonds via direct deprotonation using KTMP is described. The conversion of amorphadiene to artemisinic alcohol via a simple, highly regioselective deprotonation over 4 other possible allylic sites is shown with further extrapolation to the first large-scale telescoped chemical synthesis of artemisinic acid from amorphadiene. Finally, application of the method for the successful site-selective functionalization of unactivated allylic C-H bonds in other terpene-based natural products is also highlighted.