Whitby group

Methanesulphonylchloride (1.89 g, 16.5 mmol) was added slowly to a solution of 3-phenyl-4-penten-1-ol (319) (2.43 g, 15 mmol) and triethylamine (1.82 g, 18 mmol) in dry DCM (30 mL) at –40 °C, under Ar. After 2 h, the reaction mixture was filtered and the filtrate washed with brine, dried over MgSO₄, filtered and concentrated. A solution of the crude mesylate in dry acetone (10 mL) was added to a refluxing solution of sodium iodide (7.5 g, 50 mmol) in dry acetone (50 mL). After 1.5 h, TLC analysis showed complete consumption of starting material and the reaction mixture was allowed to cool. After pouring into saturated Na₂S₂O₃ solution (30 mL), and pentane (30 mL), the aqueous phase was extracted with pentane, and the combined organic phases washed with brine, dried over MgSO₄, filtered and concentrated. The crude product was purified by column chromatography (SiO₂, 10% ether in petrol) to give the desired iodide as a clear, colourless oil (2.509 g, 61%).