Total Synthesis of (+)-Prezizaan-15-ol, (+)-Jinkohol II, and (+)-Jinkoholic Acid

A recently developed
photochemical cascade reaction provides
access
to diastereomeric pentacyclic products, which display the carbon skeleton
of prezizane natural products. The minor diastereoisomer with a 2β-Me
configuration was converted in 12 reaction steps into (+)-prezizaan-15-ol.
The major diastereoisomer with a 2α-Me configuration gave in
an analogous route (+)-jinkohol II, which was oxidized at C13 to (+)-jinkoholic
acid. A previous ambiguity regarding the configuration of the natural
products could be clarified by total synthesis.