Stereoselective total synthesis of (±)-parthenolide and (±)-7-epi-parthenolide

The total synthesis of (±)-parthenolide and (±)-7-epi-parthenolide starting from readily available limonene has been achieved with high stereoselectivity. The key synthetic features include (i) a ring expansion reaction, Oxy-Cope rearrangement to construct the medium-sized carbocycle on large scale and (ii) substrate-controlled stereoselective introduction of the lactone and epoxy moiety at a late stage, providing a flexible method to synthesize PTL analogs. [Display omitted]