Abstract: A process for synthesizing oxygen-containing polyoxatetracycle compounds and in particular analogs of the antimalarial agent known as qinghaosu or artemisinin is disclosed. The process employs as a reactant an olefinically unsaturated bicyclic bridging ketone having nonenolizable bridgehead moieties for both of its alpha positions. This ketone is converted to a vinylsilane that is subjected to ozonolytic cleavage of its olefinic bond to yield a member of a family of unique carboxyl/carbonyl-substituted vinylsilanes which may in turn optionally be subjected to a wide range of reactions prior to a final ozonolysis/acidification step which closes the oxygen-containing ring structure. The various intermediates are claimed as aspects of this invention as are novel tetracycles and their use as antimalarials.

Abstract: A process for synthesizing polyoxa tetracyclics which involves the ozonolysis of a single-ring-structure vinyl silane with resulting direct formation of the desired multiple ring matrial. The polyoxa tetracyclic compounds have the formula ##STR1## The vinyl silanes have the structure ##STR2## The vinyl silanes are new chemical compounds as are corresponding primary ozonide and dioxetane intermediates. In a preferred embodiment, this invention provides a total synthesis of the antimalarial artemisinin.

Abstract: Introduction of a C-12 substituent and especially a .beta. C-12 substituent into glucocorticoids improves their usefulness as topical antiinflammatories by increasing their topical activity relative to their systemic activity, thus reducing systemic side effects such as adrenal suppression.