Cyclopentanone → 4-{1-Ethyl-1-[4-(1-hydroxy-cyclopentylethynyl)-3-methyl-phenyl]-propyl}-2-methyl-benzoic acid methyl ester

Participants

Reaction Steps

To a −78 C solution of 4-[1-Ethyl-1-(4-ethynyl-3-methyl-phenyl)-propyl]-2-methyl-benzoic acid methyl ester (2.50 g, 7.47 mmol) in THF (80 ml) is added lithium hexamethyldisilazide (8.22 ml, 8.22 mmol, 1.0 M in THF) and stirred at −78 C for 30 min. Cyclopentanone (730 μL, 8.22 mmol) is added and the reaction mixture warmed to room temperature. The reaction is quenched with saturated aqueous NH4Cl (30 ml) and concentrated. The residue is partitioned between EtOAc (300 ml) and 1.0N HCl (50 ml). The aqueous layer is extracted with EtOAc (100 ml). The combined organic layer are washed with water (50 ml), brine (50 ml), dried (MgSO4), concentrated and chromatographed (120 g SiO2, 5% EtOAc/Hexanes) to yield the title compound (2.45 g, 79%).

Provenance & Evidence