Imine-directed metalation of o-tolualdehyde: the use of catalytic amine base, a route to 2-(8-phenyloctyl)benzaldehyde

Ortho-tolualdehyde is metalated and alkylated through its tert-butylimine and this reaction provides a direct and efficient synthesis of 2-(8-phenyloctyl)benzaldehyde. A catalytic amount of amine base with BuLi is used to generate imine anions of different reactivities and selectivities. These reactions yield substantially higher amounts of alkylated products.