反应详情

Methyl 2-acetoxy-4-methylbenzoate was converted to a mixture of methyl 4-[2-(2-benzyloxyphenyl)-(E)-ethenyl]-2-hydroxybenzoate and methyl 4-[2-(2-benzyloxyphenyl)-(Z)-ethenyl]-2-hydroxybenzoate using the procedures described in Example 8 for the synthesis of methyl 4-[2-(2-benzyloxyphenyl)ethenyl)-3-fluorobenzoate from methyl 3-fluoro-4-methylbenzoate (using 2 equivalents of lithium hexamethyldisilazide in the final step). The isomers were separated by subjecting to chromatography on silica gel using a dichloromethane:hexane (1:2) as eluant. Further purification of the isomers was achieved by crystallisation.

1. customThe isomers were separated
2. customFurther purification of the isomers
3. customwas achieved by crystallisation