کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
43902 | 45994 | 2007 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Solid acid catalysis of tandem isomerization-lactonization of olefinic acids Solid acid catalysis of tandem isomerization-lactonization of olefinic acids](/preview/png/43902.png)
The conversion of unsaturated acids to γ-lactones is catalyzed by the solid sulfonic acid catalysts Amberlyst-15 and Nafion SAC-13 in refluxing chlorobenzene. For 3- and 4-enoic acids, in which double bond migration is not required for γ-lactone formation, yields are 95–100%. For 5-, 6-, 9-, and 10-enoic acids, the lactone yield decreases from 95% to 25% as the distance between the olefin and carboxylic acid groups increases. Amberlyst-15 is the preferred catalyst in these reactions because of its lower cost and reusability.
The 5-, 6-, 9-, and 10-enoic acids (a) undergo tandem olefin migration followed by cyclization to give γ-lactone (b) products in 25-95% yields in the presence of Amberlyst-15 in refluxing chlorobenzene. In all of these reactions, the δ-lactone (c) forms initially and then rearranges to the final γ-lactone (b) product.Figure optionsDownload as PowerPoint slide
Journal: Applied Catalysis A: General - Volume 333, Issue 2, 15 December 2007, Pages 238–244