1-Pyrrolidinecarboxylic acid, 3-ethynyl-, 1,1-dimethylethyl ester

90965-06-3

59379-02-1

287193-00-4

GENERAL STEPS: 1-Boc-3-pyrrolidinecarboxaldehyde (580 mg, 2.91 mmol) was dissolved in methanol (15 mL) at room temperature, and potassium carbonate (1.00 g, 7.28 mmol) and dimethyl (1-diazido-2-oxopropyl)phosphonate (839 mg, 4.37 mmol) were added sequentially. The reaction mixture was stirred at room temperature for 3 h. After completion of the reaction, it was filtered through a short diatomaceous earth pad and the filtrate was concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography with an eluent gradient of 0 to 50% ethyl acetate/hexane to give a colorless oily product. The product was allowed to stand in a refrigerator and cured to give 1-Boc-3-ynylpyrrolidine white solid (374 mg, 66% yield).