Ethyl formate → sodium (Z)-3-ethoxy-3-oxoprop-1-en-1-olate

Sodium hydride (21.79 g, 545 mmol) was suspended in isopropyl ether (378 mL) in a 3-neck flask equipped with a thermometer adapter, addition funnel and a capped neck. Ethyl acetate (44.4 mL, 454 mmol) was added slowly via syringe through the capped neck. An internal temperature of 45° C. was maintained. Ethyl formate (78 mL, 962 mmol) was added via the addition funnel slowly, maintaining the temperature at 42° C. The reaction was allowed to stir overnight, at which point solid had crashed out. This solid was filtered and washed with ethyl ether (2×100 mL) and hexanes (200 mL) and the solid was dried to give the title compound.