HCID 18391509, compound → trans-4-Carboxy-L-proline

Participants

Reaction Steps

N-CBZ-trans-4-carboxy-L-proline (0.458 g, 1.56 mmol) was dissolved in methanol (50 mL) and transferred into a Parr shaker bottle. After adding 10% Pd-C (0.080 g), the mixture was shaken under an atmosphere of hydrogen at 48-50 psi for 0.5 h on the Parr apparatus. The catalyst was removed by filtration through Celite and the filter cake was washed with water. The combined filtrate and washings were concentrated in vacuo to yield a white solid, which was recrystallized from H2O-EtOH-acetone to yield 0.187 g (75%) of 7 as colorless prisms: mp 219°-220° C. (lit. 18 mp 223°-225° C.); [α]25D -54° (c 1.04, H2O) [lit. 18 [α]20D -46.0° (c 1.0, H2O)]; 1H NMR (300 MHz, D2O) δ 4.28 (dd, J=8.6, 7.3 Hz, 1 H, H-2), 3.68-3.57 (m, 2 H, H-5), 3.38-3.29 (m, 1 H, H-4), 2.59 (ddd, J=13.7, 8.6, 6.0 Hz, 1 H, H-3), 2.42 (ddd, J=13.7, 8.1, 7.3 Hz, 1 H, H-3); 13C NMR (75.5 MHz, D2O) δ 178.99, 176.30, 63.67, 50.32, 45.24, 35.18; IR (KBr) 3600-2200 (broad), 1720, 1610, 1515, 1360, 1335, 1285, 1220, 1185 cm -1 ; LRMS (EI, 70 eV) m/e 159 (M+, 19), 114 (100), 87 (53), 68 (92). Anal. Calcd for C6H9NO4 : C, 45.28; H, 5.70; N, 8.80. Found: C, 45.21; H, 5.64; N, 8.68.

Provenance & Evidence