反应详情

A stirred suspension of 2,6-dichlorobenzyltriphenylphosphonium bromide (2.5 g) in dry tetrahydrofuran (30 mL) is treated dropwise with a solution of potassium t-butoxide (0.56 g) in dry tetrahydrofuran (32 mL) at 0° C. After stirring at this temperature for 1 hour, it is treated with a solution of 3-cyclopentyloxy-4-methoxybenzaldehyde (1.1 g) in dry tetrahydrofuran (15 mL). The reaction mixture is stirred from 0° C. to 5° C. for 1.5 hours, and then allowed to warm to room temperature. After stirring overnight, the mixture is concentrated and the resulting residue is treated with ethyl acetate (200 mL). The resulting organic solution is filtered. The filtrate is concentrated and the resulting residue is subjected to flash chromatography, eluting with dichloromethane, to give trans-1-(3-cyclopentyloxy-4-methoxyphenyl)-2-(2,6-dichlorophenyl)ethene (1.16 g), m.p. 47-49° C. [Elemental analysis: C, 66.4; H, 5.6; Cl, 19.4%, calculated: C, 66.1; H, 5.55; Cl, 19.5%].

1. stirringThe reaction mixture is stirred from 0° C. to 5° C. for 1.5 hours
2. stirringAfter stirring overnight
3. concentrationthe mixture is concentrated
4. additionthe resulting residue is treated with ethyl acetate (200 mL)
5. filtrationThe resulting organic solution is filtered
6. concentrationThe filtrate is concentrated
7. washeluting with dichloromethane