网站首页/有机反应/还原反应/酮还原成亚甲基反应——LAH-AlCl3 或 LAH 法还原
酮还原成亚甲基反应——LAH-AlCl3 或 LAH 法还原

 一般而言,该方法主要用于芳基酮或二芳基酮的还原. 如芳环上带有许多富电子基团或二芳基的酮,这类还原易于进行有时不需要加任何 Lewis 酸.

LAH-AlCl3 法示例1

    A solution of AlCl 3 (106.7 g, 0.8 mol) in diethyl ether (200 mL) was added slowly to a stirred  slurry of LiAlH 4 (15.2 g, 0.4 mol) in ether (100 mL), and the mixture was stirred for 5 min. A solution of 4-methylbenzophenone (49.1 g, 0.25 mol) was then added dropwise, while the reaction mixture was stirred. The exothermic reaction kept the mixture refluxing. When the refluxing stopped, the mixture was stirred for another 15 min, and ethyl acetate (53 mL, 0.55 mol) was added dropwise to decompose excess reagent. The mixture was poured onto ice (300 g) and NH 4 Cl (85 g), and the ethereal layer was separated and washed with saturated sodium chloride solution (100 mL). The aqueous layer was extracted with dichloromethane (2*100 mL), the extracts were combined with the ether solution and driedwith MgSO 4 , and the solvent was evaporated. The crude product was distilled under vacuum (bp 112 o C/0.05 Torr) to yield a pure colorless liquid (42.9 g, 94%). 'H NMR (60 MHz, CDCI,) δ 2.31 (s, 3H, CH,), 3.95 (s, 2 H, CH2), 7.10 (s, 4 H, arom), 7.23 (m, 5 H, arom); MS m/z (re1 intensity) 182 (M + , 74), 181 (18), 167 (IOO), 166 (24), 165(47), 152 (18), 91 (10).

LAH直接还原二芳基酮示例2

    A solution of benzophenone (42 g, 0.2 mol) in ether (400 mL) was added dropwise to a solution of lithium aluminum hydride (35.6 g, 0.93 mol) in ether (1400 mL) and the mixture was bolied under reflux for 6 g. The solution was cooled. Then 36 mL of water was added dropwise. The solid was removed and filtrate was concentrated and the risidue distilled (bp 88-90 at 0.027 mmHg) to afford the product (22 g, 61 %), which on collong solidified; mp 30-32 °



纳孚服务
  • 化学试剂
  • 提供稀有化学试剂现货

  • 化学试剂定制合成服务
  • 上海纳孚生物科技有限公司提供市场稀缺的化学试剂定制服务

  • 新材料现货
  • 上海纳孚生物科技有限公司代理或自产包含石墨烯产品,类石墨烯产品、碳纳米管、无机纳米材料以及一些高分子聚合物材料

  • 结构设计及定制合成
  • 可以根据客户需求对所需化合物结构进行设计改性,从而定制合成出客户所需分子式结构

  • 联系我们
  • 021-58952328
  • 13125124762
  • info@chemhui.com
  • 关注我们
在线客服
live chat