Hexamethylphosphoramide → HCID 19041732, compound

Participants

Reaction Conditions

Reaction Steps

n-BuLi (1.6M in hexane, 1.5 mL, 2.4 mmol) was slowly added to 2,2,6,6-tetramethylpiperidine at 0° C. and the slurry was stirred 10 min, then cooled to -78° C. and diluted with 6 mL (oxygenated) THF. The ester from Example 3, Step 2 (880 mg, 1.92 mmol) dissolved in 3 mL THF (O2) was added and the resulting mixture was stirred-- h at -78° C. and 1 h at -45° C. HMPA (668 μL, 3.8 mmol) was added and the mixture was stirred another 2 h at -30° C., then warmed to 0° C. The reaction was quenched with aq. NaHSO3 and then partitioned between saturated NH4Cl and ethyl acetate; the organic layer was washed with water, brine and dried over MgSO4. Purification by flash chromatography (40% ethyl acetate in hexane) provided 230 mg of the title compound.

Provenance & Evidence