Fortschritte Der Chemie Organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products : Springer : 9783709187920 : 3709187923 : 01 Mar 2012 : More than ten years have elapsed since the publication of a compre­ hensive review on the quassinoids, the bitter principles of the Simaroubaceae family (80). Interest in these terpenoids has increased enormously in recent years due in part to the finding of the American National Cancer Institute in the early 1970s that these compounds display marked antileukemic activity. Furthermore, a wide spectrum of other biological properties for the quassinoids has been discovered and studies on chemical modifications of inactive members to yield biologically active ones were undertaken. New structures have been established also and numerous synthetic approaches have been developed which include the total synthesis of the parent compound, quassin (p. 250) and also that of castelanolide (p. 253). It is intended that this present chapter wi