Trifluoroacetic acid → racemic 2-oxo-2-phenylethyl (3R,4S)-4-allyl-3-azidopyrrolidine-3-carboxylate trifluoroacetate

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Reaction Steps

While under nitrogen, a solution of racemic 1-tert-butyl 3-(2-oxo-2-phenylethyl) (3R,4S)-4-allyl-3-azidopyrrolidine-1,3-dicarboxylate (0.425 g, 1.02 mmol) in methylene chloride (4 mL) was treated with trifluoroacetic acid (1.2 mL, 15 mmol) quickly dropwise, and the resulting homogeneous mixture was stirred at room temperature. After 40 min, the mixture was concentrated under reduced pressure and dried under high vacuum for several hours to give crude racemic 2-oxo-2-phenylethyl (3R,4S)-4-allyl-3-azidopyrrolidine-3-carboxylate trifluoroacetate as a dark amber viscous oil which was used immediately in the next step. LC-MS ESI+MS found for C16H18N4O3 m/z 315.2 (M+H). 1H NMR (CDCl3, 400 MHz) δ 7.92 (m, 2 H), 7.69 (m, 1 H), 7.55 (m, 2 H), 5.75 (m, 1 H), 5.62 (m, 2 H), 5.24 (d, J=17 Hz, 1 H), 5.20 (d, J=10.2 Hz, 1 H), 4.08 (m, 1 H), 3.80 (m, 1 H), 3.55 (m, 2 H), 2.80 (m, 1 H), 2.63 (m, 1 H), 2.27 (m, 1 H).

Provenance & Evidence