A proposal of synthesis of maoecrystal V

In 2004, islolated was the maoecrystal V with a novel C19 skeleton from the leaves of a Chinese medicinal herb, Isodon eriocalyx. it is remarkably active against HeLa cells (IC50) 0.02 ug/mL).
The two chiral quaternary carbons and a tertiary alcohol in a contiguous setting served to pose interesting challenges to the science of chemical synthesis.
So far, no total synthesis. the following are just my thoughts.











another one. not better.










or umpolung chemistry.(sorry, one methyl is missing in the product).