Practical generation of 3,5-dimethoxybenzyllithium: application to the synthesis of 5-substituted-resorcinols

Reductive lithiation of 3,5-dimethoxybenzyl methyl ether was successfully performed with lithium wire and a catalytic amount of naphthalene in dry tetrahydrofuran at -15 degreesC, leading to the quantitative generation of 3,5-dimethoxybenzyllithium. This organometallic compound, which can be stored for at least 24 h, was trapped with a variety of different electrophiles, including, besides aldehydes, non-functionalized and functionalized. alkyl halides and an epoxide. Accordingly, it is a useful intermediate in the synthesis of 5-substituted natural and non-natural resorcinols. Copyright (C) 2003 John Wiley Sons, Ltd.