M-Cresol → (S)-methyl 3-(m-tolyloxy)-2-(tritylamino)propanoate

Participants

Reaction Steps

To a round-bottom flask equipped with a stir bar was added (S)-methyl 3-hydroxy-2-(tritylamino)propanoate (10.0 g, 27.7 mmol), triphenylphosphine (7.98 g, 30.4 mmol) and toluene (100 mL). The solution was stirred at room temperature for 30 min., then to the solution was added m-cresol (3.78 mL, 36.0 mmol) and diisopropylazodicarboxylate (“DIAD”, 5.92 mL, 30.4 mmol). The solution was heated at 80° C. with stirring for 18 h. The solution was cooled to room temperature and concentrated and the resulting residue was subjected to silica gel chromatography (hexanes:EtOAc) to afford (S)-methyl 3-(m-tolyloxy)-2-(tritylamino)propanoate, 8.28 g (66%). 1H-NMR (400 MHz, CDCl3) δ 7.53 (d, J=7.6 Hz, 6H), 7.29-7.23 (m, 5H), 7.21-7.11 (m, 4H), 6.77 (d, J=7.3 Hz, 1H), 6.73-6.64 (m, 2H), 5.30 (s, 2H), 4.25 (dd, J=9.3, 4.9 Hz, 1H), 4.01 (dd, J=9.2, 6.7 Hz, 1H), 3.76-3.68 (m, 1H), 3.22 (s, 3H), 2.88 (d, J=10.5 Hz, 1H), 2.32 (s, 3H).

Provenance & Evidence