Application of the BHQ benzannulation reaction to the synthesis of benzo-fused coumarins

A new approach to the synthesis of the 6H-benzo[d]naphtha[1,2-b]pyran-6-one ring system present in the gilvocarcin family of antibiotics is described. The key feature of this approach is the application of a new benzannulation strategy (the ‘BHQ Reaction’) whereby readily available ortho-allylaryl trichloroacetates are transformed into naphthalene derivatives via a cascade of reactions involving an initial ATRC reaction followed by the extrusion of CO2.