تفاعل #47110

معادلة التفاعل

4-chromanol

dichloromethane

ethyl diazoacetate

→

product 475

[(1-Benzopyran-4-yloxy)methyl]acetic acid ethyl ester

المذيبات

heptane

ظروف التفاعل

المعالجة

1. 1
   ترشيحfiltered through Celite
2. 2
   أخرىthe filtrate is evaporated
3. 3
   أخرىthe residue purified by chromatography on silica gel
4. 4
   غسيلelution with EtOAc:dichloromethane:hexane (10:20:70)

الإجراء التجريبي

To a solution of 4-chromanol (1.5 g, 10.0 mmol) in dichloromethane (20 mL) is added rhodium (II) acetate dimer (10 mg) followed by ethyl diazoacetate (0.95 mL, 9.0 mmol). The reaction mixture is stirred at rt for 30 min. The reaction mixture is diluted with heptane, filtered through Celite, and the filtrate is evaporated and the residue purified by chromatography on silica gel; elution with EtOAc:dichloromethane:hexane (10:20:70) gives 1.81 g of the product 475. 1H NMR (CDCl3) δ 7.35 (dd, 1H), 7.22 (dt, 1H), 6.90 (t, 1H), 6.84 (d, 1H), 4.56 (m, 1H), 4.36 (dd, 1H), 4.29 (dd, 1H), 4.23 (q, 2H), 4.19 (s, 2H), 2.18 (m, 1H), 2.05 (m, 1H), 1.30 (t, 3H); MS: m/z 236 (M++1).

المصدر