DIRECTED LITHIATIONS - THE EFFECT OF VARYING DIRECTING GROUP ORIENTATION ON COMPETITIVE EFFICIENCIES FOR A SERIES OF TERTIARY AMIDE, SECONDARY AMIDE, AND ALKOXIDE DIRECTED ORTHO LITHIATIONS

Significant differences for competitive efficiencies in directed ortho lithiations for single functional groups in three series, the secondary benzamides 1-4, the tertiary benzamides 5-11, and the benzylic alcohols 12-17, are reported. For both amide series the efficiencies increase as the oxygen and ortho hydrogen in the substrate are more coplanar with the aromatic ring; however, for the alcohol series the opposite order is observed. Rationalizations are offered for these observations.