當(dāng)鄰位和對(duì)位有吸電子基團(tuán)存在時(shí)，此體系去甲基化容易進(jìn)行。此條件下，乙基和異丙基也可以脫去。底物中有醛和酯時(shí)，去甲基需要更長(zhǎng)的時(shí)間，但產(chǎn)率還是很好的。底物中有甲酯會(huì)去甲基形成酸。
Cleavage of 2,3-Dimethoxybenzaldehyde. 2,3-Dimethoxybenzaldehyde (1.0 g,6 mmol) and LiCl (0.76 g,18 mmol) are heated in boiling DMF (10 mL), the reaction being monitored by GLC. When the starting material disappears, 10% aqueous NaOH (30 mL) is added;the solution is washed with ether (2×25 mL), then acidified with 10%aqueous HCl (50 mL), and extracted with ether (2×25 mL). The organic phase is washedwith brine (30 mL), dried (sodium sulfate) and concentrated in a rotaryevaporator to afford 2-hydroxy-3-methoxybenzaldehyde (0.88 g, 98%).
【A.M. Bernard, M. R. Ghiani, P. P. Piras and A. Rivoldini, Synthesis,1989, 287】
