Water → Hexyl 2,2-bis(hexyloxy)propanoate

Beteiligte Stoffe

Reaktionsschritte

To a solution of methyl pyruvate 1 (10.0 g, 98.0 mmol) in toluene (100 mL) is added 1-hexanol 2 (40.1 g, 392 mmol) and p-TsOH (186 mg, 0.98 mmol). The mixture is heated to reflux for 10 hours with azeotropic removal of water from the reaction mixture. The reaction is quenched with saturated NaHCO3 (100 mL), and the reaction mixture is extracted with ethyl acetate (2×100 mL). The combined organic layers are washed with brine (100 mL) and dried over anhydrous sodium sulfate. The solvent is removed and the residue is purified by silica gel chromatography (1→10% ethyl acetate/hexane) to give hexyl 2,2-bis(hexyloxy)propanoate 3 (29.5 g, 84%) as a colorless oil: Rf (15% EtOAc/hexane)=0.53; IR (thin film, cm−1) 2956, 2930, 2860, 1746 (C═O), 1467, 1280, 1137, 1062. 1H NMR (600 MHz, CDCl3) δ 4.14 (t, J=7.2 Hz, 2H), 3.48 (ddd, J=9.0, 7.2, 6.6 Hz, 2H), 3.35 (ddd, J=9.0, 7.2, 6.6 Hz, 2H), 1.65-1.63 (m, 2H), 1.59-1.54 (m, 4H), 1.49 (s, 3H), 1.35-1.24 (m, 18H), 0.86 (t, J=7.2 Hz, 9H); 13C NMR (150 MHz, CDCl3) δ 170.2, 99.5, 65.4, 62.6, 31.7, 31.3, 29.7, 28.5, 25.8, 25.5, 22.6, 22.5, 21.9, 14.0, 13.9.

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