Nature electrocyclization cascade

An Electrocyclization Cascade in Nature Immunosuppressants from Streptomyces Cultures... 

The electrocyclization cascade that assembles the endiandric acids, sequential thermal 871-comotation followed by 671-disrotation, is a recurring theme in natural product... 

Electrocyclizations often produce six-membered dienes or four-membered strained enes which can be part of a cydoaddition if appropriate reaction partners such as enes or dienes are available. Such cascades are able to quickly generate highly complex obgocydic frameworks with excellent stereocontrol [41], The Trauner group has made remarkable contributions to this field and has exploited this field for elegant and efficient natural product syntheses. An example yielding the tricycUc core structure of the fungal polyketide (—)-PF-1018 is presented in Scheme 6.25. 

---