反应详情

Ethyl 3-(4-benzyloxyphenyl)but-2-enoate (3.4 g) in ethyl acetate (100 ml) was hydrogenated over a 10% palladium-on-carbon catalyst (250 mg) at atmospheric pressure/ambient temperature. The catalyst was removed by filtration and the filtrate evaporated to give an oil. The oil was purified by chromatography on silica gel using a 4/1 (v/v) mixture of hexane and ethyl acetate as eluent to give ethyl 3-(4-hydroxyphenyl)butanoate (1.51 g) as a pale yellow oil; NMR(CDCl3): 1.20(3H,t), 1.27(3H,d), 2.52(2H,q), 3.22(1H,m), 4.08(2H,q), 4.84(1H,s), 6.71(2H,m) and 7.08(2H,m); m/z 208(M). Ethyl 3-(4-allyloxyphenyl)butanoate was prepared using the procedue used to prepare ethyl 3-(4-allyloxyphenyl)propionate (see Example 1) but using ethyl 3-(4-hydroxyphenyl)butanoate in place of ethyl 3-(4-hydroxyphenyl)propionate; NMR(CDCl3) 1.17(3H,t), 1.25(3H,d), 2.51(2H,m), 3.22(1H,m), 4.05(2H,q), 4.50(2H,m), 5.33(2H,m), 6.06(1H,m), 6.82(2H,m) and 7.11(2H,m); m/z 249 (M+H).

1. customThe catalyst was removed by filtration
2. customthe filtrate evaporated
3. customto give an oil
4. customThe oil was purified by chromatography on silica gel using
5. additiona 4/1 (v/v) mixture of hexane and ethyl acetate as eluent