Highly enantioselective preparation of tricyclo[4.4.0.05,7]decene derivatives via catalytic asymmetric intramolecular cyclopropanation reactions of α-diazo-β-keto esters

The enantioselective preparation of the tricyclo[4.4.0.05,7]dec-2-ene derivatives via the catalytic asymmetric intramolecular cyclopropanation (CAIMCP) reactions of α-diazo-β-keto esters with excellent ee (95–98% ee) is described. The chiral building blocks reported herein would be versatile intermediates for enantioselective natural products synthesis.