Competition of substituents for ortho direction of metalation of veratric acid

Nguyet Trang Thanh Chau (1) , Thi Huu Nguyen (1) , Anne-Sophie Castanet (1) , Kim Phi Phung Nguyen (2) , Jacques Mortier (1)

1 UCO2M - Unité de chimie organique moléculaire et macromoléculaire
2 Ecole des Sciences Naturelles Ho Chi Minh Ville

LTMP (5 equiv) metalates randomly veratric acid (1). Under external quench conditions, the thermodynamically more stable lithium 2-lithio-3,4-dimethoxybenzoate (2) reacts with a variety of electrophiles to give versatile building units that are not easily accessible by conventional means. Under in situ quench conditions (LTMP/TMSCl), a reversal of regioselectivity is observed and 6-trimethylsilyl-3,4-dimethoxybenzoic acid (10) is formed predominantly.

Mots clés: ortho-lithiation; organolithiums; benzoic acids

Domaines: Chimie organique

Nguyet Trang Thanh Chau, Thi Huu Nguyen, Anne-Sophie Castanet, Kim Phi Phung Nguyen, Jacques Mortier. Competition of substituents for ortho direction of metalation of veratric acid. Tetrahedron, 2008, 64 (46), pp.10552-10557. ⟨10.1016/j.tet.2008.08.086⟩. ⟨hal-00326919⟩