Bicycloheptanes as Intermediates in the Synthesis of Steroids. Total Synthesis of Estrone

Article abstract of DOI:10.1021/jo01299a042

A synthesis of dl-estrone has been accomplished by employing the key bicyclo<2.2.1>heptene intermediate 2 prepared from ketal ester 16 via a series of reactions featuring the remarkable stereospecific alkylation of 16 with 2-(4-methoxybenzocyclobutenyl)et