A-nor B-aromatic steroidal skeleton was efficiently constructed by means of o-quinodimethane chemistry with exclusive stereoselectivity. The benzocyclobutene substrate for generation of the o-quinodimethane intermediate and subsequent [4+2] cycloaddition could be synthesized via (E)-selective Julia–Kocienski olefination and diastereoselective Grignard addition reactions. The synthesized tricyclic steroid-like compound with a trans-diol substructure would be utilized for divergent syntheses of potentially antitumor OSW-1 analogues with the truncated steroidal aglycone.