利用铬酰氯将芳基或环烷基上的甲基氧化为醛基的反应。以法国化学家Alexandre Léon Étard (5 January 1852, Alençon – 1 May 1910)的名字命名。将甲苯氧化为苯甲醛是非常重要的一个应用。此反应通常产率较低，延长反应时间到几天甚至几周可能会得到较好的收率。利用Bredereck试剂也能实现此转化。

反应机理

反应中先生成Étard络合物，如果想得到纯度较高的醛，应该在络合物水解前对其进行纯化。

反应实例

Cyclohexanecarboxaldehyde (3). Chromyl chloride (77.5 g, 0.5 mol) in CCl4 (155 mL) was added slowly to methylcyclohexane 1 (47 g, 0.5 mol) in CCl4 (100 mL) at 33–38 C over 5 h. After 15 min of stirring, 2-methylbutene (3 mL) was added and after 5 days the chromyl complex 2 was filtered (87 g, 70%) and added to 500 g of ice. After extraction with Et2O and evaporation of the solvent, the residue was distilled in vacuo to afford 5.5–5.8 g of 3 (10%)

相关文献

1 Etard AL Bull Soc Chim Fr 1877 27 249(1)

2 Ferguson LN Chem Rev 1946 38 227

3 Hartfort WH Chem Rev 1958 58 1

4 Bisagni E Bull Soc Chim Fr 1968 637

5 Nenitzescu CD Rev Roum Chim 1969 14 1553

6 Moore WJ J Org Chem 1993 58 512

7 Jaworska M J Am Chem Soc 2003 125 13956

8 Tia R Inorg Chem 2009 48 11434

编译自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 145.