Sodium, 2,4-cyclopentadien-1-yl- → 2-methoxyethylcyclopentadiene

To a solution of 19.7 g(85.7 mmol) 2-methoxyethyltosylate as prepared in step (a) in 200 ml THF cooled to 0° C. was added 55 ml of 2.0M (110 mmol) sodium cyclopentadienylide in THF. The reaction mixture was allowed to warm to room temperature and was stirred for 16 h. 100 ml concentrated aqueous saline solution was added and the product extracted with diethyl ether (3×75 ml). The combined organic fractions were dried over sodium sulphate for 16 hrs, filtered and the solvents removed under reduced pressure using a rotary evaporator to yield a brown oil. The crude product was distilled under reduced pressure (b.p. 40-°44° C. at 2-3 mm Hg) to give 4.5 g of a colourless oil (37.7 mmol, 44.0%).