Studies on Anthelmintics. VIII

The Constitution and Stereochemistry of Artemisin1,2

“…This is in accord with Barton's conclusion.8 As a consequence, the Cg-0 and the C7-C11 bonds are both equatorially oriented, as a 6-5 ring fusion cannot exist in a diaxial configuration with chairformed cyclohexanes, in close resemblance to the santonin series. 28 It was further expected that a more complete view on the stereochemistry of artemisin could be obtained by effecting the direct correlation of this compound with santonin whose configurations have been established.29-32 Two transformation pathways have been selected for achieving this.…”