Intramolecular Friedel–Crafts Arylation of Achmatowicz Rearrangement Products for Construction of 1,5-Oxygen-Bridged Medium-Sized Carbocycles

The first intramolecular Friedel-Crafts arylation of Achmatowicz rearrangement (AchR) products is achieved, providing 1,5-oxygen-bridged medium-sized carbocycles 9-oxabicyclo[3.3.1]nonanes (9-OBNs) or 10-oxabicyclo[4.3.1]decanes (10-OBDs). The efficiency and utility of this protocol were demonstrated by a broad substrate scope (31 examples), excellent scalability (gram scale), and versatile transformations of products. Additionally, this FeCl3 protocol allows for Prins cyclization of Achmatowicz rearrangement products and an intermolecular Friedel-Crafts reaction, which extends the application of Achmatowicz rearrangement.