An efficient synthesis of 10-substituted benzo[b]phenanthro[9,10-d]furans

Lithiation of benzo[b]phenanthro[9,10-d]furan in THF at -78° gives the corresponding intermediates which by reaction with the appropriate electrophiles afford 10-substituted benzo[b]phenanthro[9,10-d]furans. A study concerning the reactivity of the title compds. was performed by ab-initio calcns. and their structure confirmed. [on SciFinder(R)]