Conversion of Ester Moieties to 4-Bromophenyl Groups via Electrocyclic Reaction of Dibromocyclopropanes.

Conversion of ester moieties into 4-bromophenyl groups was effected by means of a four-step protocol: a Grignard reaction of the ester with allylmagnesium halides, a ring-closing metathesis, dibromocyclopropanation, and an electrocyclic reaction of the dibromocyclopropanes.