Réaction #47110

Équation de réaction

4-chromanol

dichloromethane

ethyl diazoacetate

→

product 475

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

Solvants

heptane

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source