Abstract Although proton abstraction from the 4-position of 2, 2-difluoro-1, 3-benzodioxole occurs with exceptional ease, lithiation of the more-remote 5-position can only be brought about if no oxygen-adjacent site remains unoccupied. Thus, unlike 4-bromo-2, 2-difluoro-1, 3-benzodioxole (1),(7-bromo-2, 2-difluoro-1, 3-benzodioxol-4-yl) triethylsilane (5b) does react with lithium diisopropylamide to generate an intermediate that isomerizes ...
