Propargyl alcohol → Prop-2-ynyl 3-oxopentanoate

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 3-ketopentanoate (3) (822 mg, 6.00 mmol) and 2-propynol (686 mg, 12.0 mmol) in toluene (7 mL) is added I2 (46 mg, 0.18 mmol). The mixture is stirred at 115° C. for 6 h, then cooled to room temperature, and extracted with ethyl acetate (100 mL). The extract is washed (brine) and dried. After solvent removal at reduced pressure, the residue is distilled (125-130° C., 2 mm) to give 401 mg (43%) of 4 as a colorless liquid. IR 3345, 2856, 1715, 1456 cm−1; 1H NMR (CDCl3) δ 1.10 (t, J=7.5 Hz, 3H, CH2CH3), 2.52 (t, J=2.4 Hz, 1H, CH≡CCH2), 2.58 (q, J=7.5 Hz, 2H, CH2CH3) 3.51 (s, 2H, CH2), 4.74 (d, J=2.4 Hz, 2H, CH≡CCH2).

Provenance & Evidence