Compound 3 (7.0 mmol) was dissolved in dry toluene (50 mL) and NaH (8.4 mmol, 60% in mineral oil) was added at 78oC. The reaction mixture was stirred at 78oC for 2 h, after which the geranyl bromide (2.3 mmol) was added at room temperature. The mixture was stirred for 4 h at 78oC, then quenched by the addition of saturated NaCl, and the organic layer was separated and dried over anhydrous Na2SO4. It was then filtered and concentrated to give a residue, which was purified over silica gel (petroleum ether: EtOAc = 20:1) to produce compound 4e as a white solid
