Sodium Hydroxide → N-Boc-cis-4-hydroxy-L-proline methyl ester

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Reaction Steps

To a solution of (2S,4S)-1-t-butoxycarbonyl-4-formyloxy-2-methoxycarbonylpyrrolidine (5.12 g: 18.7 mmole) in methanol (51.0 ml), aqueous 1N-sodium hydroxide (18.7 ml) is added under ice cooling. The mixture is stirred at the same temperature for 20 minutes to give (2S,4S)-1-t-butoxycarbonyl-4-hydroxy-2-methoxycarbonylpyrrolidine (4.09 g). Yield: 89%. Colorless crystals. NMR δ(CDCl3) ppm: 1.44(d, J=8.2 Hz, 9H), 2.0 to 2.2(m, 1H), 2.2 to 2.5(m, 1H), 3.2 to 3.8(m, 3H), 3.79(d, J=2.8 Hz, 3H), 4.2 to 4.5(m, 2H). IR ν (KBr) cm-1 : 3460, 1728, 1677.

Provenance & Evidence