Side‐Chain Retention During Lithiation of 4‐Picoline and 3,4‐Lutidine: Easy Access to Molecular Diversity in Pyridine Series

The first direct ring‐selective lithiation of 4‐picoline and 3,4‐lutidine has been achieved through the use of BuLi/LiDMAE aggregates to prevent the usual side‐chain metallation. Several functionalities have been introduced at the C‐2, C‐6 and C‐5 positions by ring‐selective sequential lithiation, opening a simple and fast route to polysubstituted pyridine building blocks. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)