Total Synthesis 11: Curcusone A

Curcusone A is a natural product, a complex diterpene featuring a characteristic [6−7−5] tricyclic carbon skeleton, that has demonstrated potent anticancer activity against a broad spectrum of human cancer cell lines.

Synthesis steps:
1.1. Extended silyl enol ether formation.
1.2. And vinylogous Mukaiyama aldol reaction.
2. Reduction of the aldehyde to an alcohol.
3. Mitsunobu reaction.
4. Claisen rearrangement. And further cyclization of the rearranged product.
5. 1,2-addition of the lithiated ethyl vinyl ether.
6. FeCl3-promoted cascade reaction.
7. Johnson alpha-iodination.
8. Stille cross-coupling reaction.
9. Alpha-methylation of the enone.

Reference:
J. Am. Chem. Soc. 2021, 143, 11, 4379. https://doi.org/10.1021/jacs.1c00557