Stereoselective Insertion of Benzynes into Lawsones: Synthesis of Biologically Important Benzannulated Bicyclo[3.3.0]octanes

An ideal stereoselective insertion of in situ generated benzynes into lawsones through domino formal [2+2]‐cycloaddition followed by rearrangement is disclosed. The reaction allowed for the preparation of biologically important benzannulated bicyclo[3.3.0]octanes in good yields and with excellent selectivities by using simple substrates and conditions. An ideal stereoselective insertion of in situ generated benzynes into lawsones through domino formal [2+2]‐cycloaddition–rearrangement is disclosed. The method gave access to biologically important benzannulated bicyclo[3.3.0]octanes in good yields and with excellent selectivities.