To a solution of 2.06 g (10 mmol) of 4-octylphenol in 50 mL of THF was added 0.85 g (15 mmol) of powdered KOH and 3.98 g (15 mmol) of 18-crown-6. The solution was heated to 50° C. for 15 minutes, whereupon 2.8 g (15 mmol) of methyl 4,4-diethoxy-2-butynoate was added. The mixture was stirred for 30 minutes, then allowed to cool to room temperature. The solution was then poured into water, and extracted 3 times with 40 mL of ethyl acetate. The organic layers were combined, dried (MgSO4) and concentrated. The crude oil was subjected to column chromatography on SiO2. Elution with 20% ethyl acetate-hexane yielded 2.1 g (54%) of an oil, used in the next step without further purification.
