Directed Ortho-Metalation of Unprotected Benzoic Acids. Methodology and Regioselective Synthesis of Useful Contiguously 3- and 6-Substituted 2-Methoxybenzoic Acid Building Blocks
Thi-Huu Nguyen, Anne-Sophie Castanet and Jacques Mortier*
*Université du Maine and CNRS, Unité de Chimie Organique Moléculaire et
Macromoléculaire (UMR 6011), Faculté des Sciences, avenue Olivier Messiaen,
72085 Le Mans Cedex 9, France, Email: jacques.mortier
univ-lemans.fr
T.-H. Nguyen, A.-S. Castanet, J. Mortier, Org. Lett., 2006, 8, 765-768.
DOI: 10.1021/ol0530427
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Abstract
By treatment with s-BuLi/TMEDA at -78°C, unprotected 2-methoxybenzoic acid is deprotonated exclusively in the position ortho to the carboxylate. A reversal of regioselectivity is observed when the acid is treated with n-BuLi/t-BuOK.
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Key Words
ID: J54-Y2006-590
