Lewis Acid-Induced Intramolecular Friedel−Crafts Cyclization of 1,3-Bis-exocyclic Dienes. A New Route to 4a-Methyltetrahydrofluorenes

Abstract

[reaction: see text] An efficient new method for constructing the 4a-methyltetrahydrofluorene skeleton was achieved via Friedel-Crafts intramolecular cyclization of 1,3-bis-exocyclic dienes. This strategy offers a simple and promising method for accessing complex structures.