(3R)-1-((1R,2R)-2-benzyloxycyclohex-1-yl)-2,5-dioxopyrrolidin-3-yl acetate → (3R)-1-((1R,2R)-2-Hydroxycyclohex-1-yl)-2,5-dioxopyrrolidin-3-yl acetate
Reaction equation
[C:1]([O:4][C@@H:5]1[CH2:9][C:8](=[O:10])[N:7]([C@@H:11]2[CH2:16][CH2:15][CH2:14][CH2:13][C@H:12]2[O:17]CC2C=CC=CC=2)[C:6]1=[O:25])(=[O:3])[CH3:2]>CO.[Pd]>[C:1]([O:4][C@@H:5]1[CH2:9][C:8](=[O:10])[N:7]([C@@H:11]2[CH2:16][CH2:15][CH2:14][CH2:13][C@H:12]2[OH:17])[C:6]1=[O:25])(=[O:3])[CH3:2]Participants
Procedure
To a solution of acetic acid (1R,2R)-benzyloxycyclohexyl-2,5-dioxo-pyrrolidin-3-(R)-yl ester (3a (1.1 g, 3.18 mmol) in MeOH was added 10% Pd—C (110 mg), and the reaction vessel was flushed twice with H2. The reaction mixture was agitated at ambient temperature under H2 (charged balloon). After 4 hours, the reaction mixture was filtered through a pad of Celite. The filtrate was concentrated in vacuo to give acetic acid 1R,2R-hydroxycyclohexyl-2,5-dioxopyrrolidin-3-(R)-yl ester (4a) as a white hygroscopic foam (0.82 g, 99% yield); MS (ES+) 256.1 [M+H]+, 278.0 [M+Na]+, 533.1 [2M+Na]+; 1H-NMR (400 MHz, CDCl3) δ 1.11-1.34 (m, 3H), 1.64-1.75 (m, 3H), 2.02-2.09 (m, 2H), 2.12 (s, 3H, CH3), 2.22 (br s, 1H), 2.63 (dd, 1H, J=18.0 Hz, 4.8 Hz), 3.11 (dd, 1H, J=8.8 Hz, J=18 Hz), 3.82 (ddd, 1H, J=4.16 Hz, J=10.6 Hz, J=12.8 Hz), 4.16 (ddd, 1H J=4.4 Hz, J=10.4 Hz, J=14.8 Hz), 5.34 (dd, 1H, J=8.8 Hz, J=4.8 Hz); 13C-NMR (100 MHz, CDCl3) δ 20.52, 24.16, 24.98, 27.77, 35.03, 35.40, 58.44, 67.43, 68.40, 170.11, 173.89, 174.08.
Workup
- customthe reaction vessel was flushed twice with H2
- filtrationthe reaction mixture was filtered through a pad of Celite
- concentrationThe filtrate was concentrated in vacuo
Sources & evidence
- ORD record
- ord-b9d925df439145528dd3d7fd5343c45e
- Source dataset
- uspto-grants-2011_12
- Patent number
- US08080673B2
Reaction notes
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