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 seconda ry benzamides 1-4, the tertiary benzamides 5-11, and the benzylic alco hols 12-17, are reported. For both amide series the efficiencies incre ase as the oxygen and ortho hydrogen in the substrate are more coplana r with the aromatic ring; however, for the alcohol series the opposite order is observed. Rationalizations are offered for these observation s.