利用鉻酰氯將芳基或環(huán)烷基上的甲基氧化為醛基的反應(yīng)。以法國化學(xué)家Alexandre Léon étard (5 January 1852,?Alen?on?– 1 May 1910)的名字命名。將甲苯氧化為苯甲醛是非常重要的一個(gè)應(yīng)用。此反應(yīng)通常產(chǎn)率較低，延長反應(yīng)時(shí)間到幾天甚至幾周可能會(huì)得到較好的收率。利用Bredereck試劑也能實(shí)現(xiàn)此轉(zhuǎn)化。
反應(yīng)機(jī)理
反應(yīng)中先生成étard絡(luò)合物，如果想得到純度較高的醛，應(yīng)該在絡(luò)合物水解前對(duì)其進(jìn)行純化。
反應(yīng)實(shí)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%)
相關(guān)文獻(xiàn)
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
編譯自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 145.
