合成路线1

The Grignard condensation of 5-cyanophthalide (I) with 4-fluorophenylmagnesium bromide (II) in THF gives 1-(4-fluorophenyl)-1-hydroxy-1,3-dihydroisobenzofuran-5-carbonitrile bromomagnesium salt (III), which slowly rearranges to the benzophenone (IV). A new Grignard condensation of (IV) with 3-(dimethylamino)propylmagnesium chloride (V) in THF affords the expected bis(magnesium) salt (VI), which is hydrolyzed with acetic acid to provide the diol (VII) as a racemic mixture. Selective esterification of the primary alcohol of (VII) with (+)-3,3,3-trifluoro-2-methoxy-2-phenylacetyl chloride (VIII) gives the monoester (IX) as a mixture of diastereomers. This mixture is separated by HPLC and the desired diastereomer (X) is treated with potassium tert-butoxide in toluene.