J.M. Timko and A. Yamashita, Org. Synth., 71, 72 (1993)

1. A solution of DMAP (1.22 g, 10 mmol), tetrahydrofuran (500 mL), 1-hexyne (11.0 mL, 95.7 mmol), acetic anhydride (13.2 mL, 140 mmol), triethylamine (9.8 mL, 70 mmol), pentacarbonyl[phenyl(methoxy)chromium]carbene (20.0 g, 64.0 mmol), and tetrahydrofuran (100 mL) is heated under reflux in a nitrogen a®osphere.
2. Heating is maintained until TLC indicates the chromium complex is totally consumed, ~45-60min.
3. The solution is cooled to ambient temperature and silica gel (30 g) is added. Volatile organic material is removed under reduced pressure.  The green solids are transferred to a filter funnel and washed with hexane until TLC indicates all products have been removed (5 x 100 mL).  The hexane filtrate is concentrated under reduced pressure to give crude product contaminated with chromium hexacarbonyl.  To this mixture is added isopropyl alcohol (20 mL) and the insoluble chromium hexacarbonyl removed by filtration.  The isopropyl alcohol filtrate is concentrated under reduced pressure and the crude product purified by silica gel chromatography.  Appropriate fractions are combined and the solvent removed under reduced pressure to give 1-acetoxy-2-butyl-4-methoxynaphthalene (11.8 g, 68% yield) as a light yellow oil which crystallizes on standing.