Diethyl Oxalate → Methyl 2-oxo-2-(1-oxo-6-vinyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetate

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Reaction Steps

To a 250 mL round bottom flask charged with a solution of 6-vinyl-3,4-dihydronaphthalen-1(2H)-one (intermediate 1, 400 mg, 2.323 mmol) and diethyl oxalate (0.630 mL, 4.65 mmol) in methanol (20 mL) was added sodium methoxide (25% wt in MeOH) (2008 mg, 9.29 mmol) via syringe. After the addition was complete, the dark reaction mixture was heated at reflux for 10 h. The reaction was quenched with 50% HCl aq. solution and then evaporated to remove the methanol. The aqueous residue was diluted with water (80 mL) and extracted with dichloromethane (2×100 ml). The organic layers were combined, concentrated, and purified by silica gel chromatography, (40 g Isco column, 0% to 25% ethyl acetate in hexane gradient) to yield the title compound. The compound had an HPLC ret. time=1.05/2.0 min. (condition E); MS:(M+H)=259.1.

Provenance & Evidence