Tetrahydrofuran → 3-(3-Benzyloxy-phenyl)-1-cyclopentyl-propan-1-one

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Reaction Steps

3-(3-Benzyloxy-phenyl)-propanoic acid (5 g, 19.5 mmol) from Example XXXX was taken up in thionyl chloride (20 mL) and refluxed for 2 hours. The excess thionyl chloride was removed under reduced pressure and carbon tetrachloride added and removed several times under reduced pressure to remove any excess thionyl chloride. The resulting oil was taken up in freshly distilled THF (50 mL), MnCl2 (0.49 g, 3.9 mmol) and LiCl (0.331 g, 7.8 mmol) were added. This was allowed to stir under nitrogen at room temperature until homogenous. The solution was then cooled to 0° C. with an ice bath and 2.0M cyclopentyl magnesium chloride (11.0 mL, 22 mmol) in Et2O was added dropwise to the solution over 0.5 hour. The reaction was allowed to stir for 10 minutes after addition was complete and was then quenched with 1N HCl and brine until acidic. The organics were extracted into EtOAc and then washed with brine and dried with MgSO4. The solvent was removed under reduced pressure and the residue submitted to flash chromatography (3:7 EtOAc:hexane, silica gel) to yield the title compound as a viscous oil. 1H NMR (CDCl3) δ 1.54-1.80 (br m, 8 H), 2.76 (m, 2 H), 2.80 (m, obscured, 1 H), 2.86 (m, 2 H), 5.05 (s, 2 H), 6.81 (br m, 3 H), 7.21 (br m, 1 H), 7.43 (br m, 5 H).

Provenance & Evidence