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

A recently developedphotochemical cascade reaction providesaccessto diastereomeric pentacyclic products, which display the carbon skeletonof prezizane natural products. The minor diastereoisomer with a 2 beta-Meconfiguration was converted in 12 reaction steps into (+)-prezizaan-15-ol.The major diastereoisomer with a 2 alpha-Me configuration gave inan analogous route (+)-jinkohol II, which was oxidized at C13 to (+)-jinkoholicacid. A previous ambiguity regarding the configuration of the naturalproducts could be clarified by total synthesis.

Automated summary

A recent photochemical cascade reaction has been developed to access diastereomeric pentacyclic products that possess the carbon skeleton of prezizane natural products. The minor diastereoisomer, with a 2 beta-Me configuration, was transformed into (+)-prezizaan-15-ol through 12 reaction steps. Similarly, the major diastereoisomer, with a 2 alpha-Me configuration, yielded (+)-jinkohol II in an analogous route and was further oxidized at C13 to yield (+)-jinkoholic acid. Total synthesis of these natural products helped clarify their configurations.