反应详情

A mixture of methyl 3-chloro-2,2-dimethylbut-3-enoate (33 g, 0.2 mol) and NaOH (9.6 g, 0.24 mol) in water (200 mL) was heated at reflux for 5 h. The mixture was cooled to ambient temperature and extracted with ether. The organic layer was discarded. The aqueous layer was acidified with cold 20% HCl solution and extracted ether (200 mL×3). The combined organic layers were dried and evaporated under reduced pressure to give 3-chloro-2,2-dimethyl-but-3-enoic acid (21 g, 70%), which was used directly in the next step. 1H NMR (400 MHz, CDCl3) δ 7.90 (brs, 1H), 5.37 (dd, J=2.4, 6.8 Hz, 2H), 1.47 (s, 6H).

1. temperaturewas heated
2. temperatureat reflux for 5 h
3. extractionextracted with ether
4. extractionextracted ether (200 mL×3)
5. customThe combined organic layers were dried
6. customevaporated under reduced pressure