Fenestranes are an intriguing class of highly strained molecules possessing a quaternary carbon with bonds that deviate from the canonical tetrahedral geometry. Herein we report the discovery that the natural product pleuromutilin can be used as a structurally complex starting material for the synthesis of a series of bridged cis,cis,cis,cis-[18.104.22.168]- and cis,cis,cis,cis-[22.214.171.124] oxafenestranes through a carbocation rearrangement cascade. X-ray crystallographic analysis of several cis,cis,cis,cis-[126.96.36.199]oxafenestranes shows a significant planarization of the central tetracoordinate carbon atom and demonstrates the influence of bridgehead substituents and bridging rings on planarity.
- natural products
- planar tetracoordinate carbon atom
- strained molecules
ASJC Scopus subject areas