dien

the fall of Dien Bien Phu.

奠边府的沦陷

Ring closing metathesis (RCM) of dienes to cycloalkene provides an important tool for C-C double bond formation catalyzed by metal carbene.

关环转换反应是形成双键的重要反应之一,即双烯合属烯关环得到环烯类合。