At -78°C, methyl cyanoformate (1.3 mmol, 0.1 mL) was added dropwise to a tetrahydrofuran solution of lithium tropenetenol (1.0 mmol) (3.2 mL). The reaction mixture was stirred at -78°C for 20 min, followed by the addition of glacial acetic acid (1 mL) and then silver acetate (1 mmol, 0.168 g) in glacial acetic acid (1 mL). The reaction mixture was heated to room temperature and stirred for another 30 min. Concentrated ammonium hydroxide solution was added until the solution became clear. The reaction mixture was extracted with chloroform (5 × 30 mL), and the organic phases were combined after separation. The organic phase was washed with water, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to give a light brown solid product, 2-CARBOMETHOXY-3-TROPINONE (187 mg, 95% yield).
