Antimalarial analogs of artemisinin

摘要

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.