Structural modification of oridonin via DAST induced rearrangement.

A simple and efficient protocol was developed for the syntheses of oridonin analogues, i.e. 6,20-epoxy ent -kaurane diterpenoid analogues from oridonin via diethylaminosulfur trifluoride (DAST) promoted rearrangement, most of which exhibited superior anticancer activities compared with their precursor.