Реакция #47110

Уравнение реакции

4-chromanol

dichloromethane

ethyl diazoacetate

→

product 475

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

Растворители

heptane

Условия реакции

Обработка

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

Методика

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).

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