Cleavage of the methylenedioxy moiety was readily accomplished by using BBr3 in excess followed by quenching with methanol and removal of the boron as the trimethylborate/ methanol azeotrope, to yield the catecholamine hydrobromide 5. These boron tribromide cleavage reactions were done under inert atmosphere in methylene chloride at-78 OC to produce a clean conversion to the catechol.
