反应详情

A solution of ethyl 2-diazo-3-(4hydroxyphenyl)propanoate (c.f. N. Takamura and T. Mizoguchi, Tetrahedron Lett., 1971, 4495) (8.8 g) in benzene (40 mL) was added over 30 minutes to a stirred, refluxing mixture of rhodium (II) acetate dimer (10 mg), methanol (7.9 mL) and benzene (50 mL). The mixture was heated at reflux for a further 30 minutes, then allowed to cool to room temperature overnight and washed with water (2×200 mL). The benzene solution was dried (MgSO4) and evaporated and the residual oil chromatographed twice on silica gel, firstly with 20% ethyl acetate in hexane as eluent and subsequently with 4% ethyl acetate in dichloromethane as eluent to afford the title compound as an oil.

1. temperaturerefluxing
2. temperatureThe mixture was heated
3. temperatureat reflux for a further 30 minutes
4. washwashed with water (2×200 mL)
5. dry with materialThe benzene solution was dried (MgSO4)
6. customevaporated
7. customthe residual oil chromatographed twice on silica gel, firstly with 20% ethyl acetate in hexane as eluent and subsequently with 4% ethyl acetate in dichloromethane as eluent