(Z)-1,1-dichloro-2-(4-benzyloxyphenyl)-2,3-bis(4-methoxyphenyl)cyclopropane: the synthesis and enantiomeric separation of an antitumor agent.

(Z)-1,1-dichloro-2-(4-benzyloxyphenyl)-2,3-bis(4-methoxyphenyl)cyc lopropane (5), a potential antitumor agent designed to treat breast cancer, was prepared in three steps. A stereospecific palladium-catalyzed cross coupling reaction which provided the intermediate (Z)-triaryl alkene 4 was a crucial step in the synthesis. Makosza phase transfer reaction on 4 gave the enantiomeric (Z)-dichlorocyclopropane derivatives 5 which were resolved by semipreparative HPLC on a chiral stationary phase consisting of amylose tris-3,5-dimethylphenyl carbamate coated on silica gel.