香豆素在碱性条件下经过开环关环重排为苯并呋喃的反应。

反应机理

反应实例

6-Hydroxybenzofuran-2,3-dicarboxylic acid (3). A solution of coumarin 1 (1.5 g, 6.25 mmol) in 5% KOH was heated on a water bath for 1 h. After cooling the mixture was acidified with 32%HCl and the product filtered to afford 1.1 g of 3 (78%), mp 227 ℃ (dec), crystallized from dil HCl or EA:PE.

【Holton GW, J Chem Soc., 1949, 2049】

【European Journal of Organic Chemistry, 2002, 12, 1937-1940】

【Tetrahedron Letter, 2012, 53, 3319-3321】

相关文献

1 Perkin WH J Chem Soc 1867 20 568

2 Perkin WH J Chem Soc 1871 24 37

3R Johnson IR Org React 1942 1 210

4 Holton GW J Chem Soc 1949 2049

5 Battah S J Chem Soc Perkin 2 1998 1603

编译自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 370.