Intricarene is an unprecedented trispiropentacyclic diterpene natural product. Recent studies have shown that intricarene carbon skeleton could arise biogenetically in a single cyclization step from the """"""""cembrane"""""""" carbon framework. This proposal describes a biomimetic total synthesis of intricarene with the key cyclization step being an unprecedented transannular [5+2] oxidopyrylium alkene cycloaddition. This penultimate cyclization event will create the trispiropentacyclic framework along with four of the five contiguouis stereocenters of intricarene in a single synthetic operation. Molecular modeling was used to study the conformations of the marcocyclic """"""""cembrane"""""""" precursor, justifying the possibility of a diastereoselective cyclization. ? ? ?
| Chandler, Brent D; Roland, Jason T; Li, Yukai et al. (2010) Seebach's conjunctive reagent enables double cyclizations. Org Lett 12:2746-9 |
