Dimethyl2-[2-(4-fluorophenyl)-2-oxoethyl]-2-[2-[4-(methylsulfonyl)phenyl]-2-oxoethyl]propanedioate → Dimethyl 3-(4-fluorophenyl)-4-(4-(methylsulfonyl)phenyl)cyclopent-3-ene-1,1-dicarboxylate

Participants

Reaction Steps

To a vigorously stirred mixture of 50.4 g (771 mmol) of zinc dust in 640 mL of THF at -78° C. under an atmosphere of nitrogen was added dropwise 60.4 mL (551 mmol) of titanium(IV) chloride. The reaction was warmed to ambient temperature with a water bath and then stirred at reflux for 1 hour. To the resulting dark mixture under reflux was added a solution of 15 g (32.3 mmol) of dimethyl 2-[2-(4-fluorophenyl)-2-oxoethyl]-2-[2-[4-(methylsulfonyl)phenyl]-2-oxoethyl]propanedioate (prepared above) in 20 mL of THF. The resulting mixture was stirred at ambient temperature for 16 hours, filtered through a pad of celite, rinsed with ethyl acetate, and concentrated in vacuo. The residue was partitioned between water and ethyl acetate; the organic phase was washed with brine, dried (MgSO4), and concentrated in vacuo. The residue was chromatographed on silica gel to give 6.26 g (44%) of 1-[2-(4-fluorophenyl)-4,4-dicarbomethoxycyclopenten-1-yl]-4-(methylsulfonyl)benzene which was identical to the material prepared in Step 8, Method A.

Provenance & Evidence