Water → HCID 57971679, compound

Reaction equation

C[O:2][C:3](=[O:21])[CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][C:10](=[O:20])[NH:11][O:12][CH:13]([O:15][CH2:16][CH:17]([CH3:19])[CH3:18])[CH3:14].O.[OH-].[Li+]>C1COCC1>[CH2:16]([O:15][CH:13]([O:12][NH:11][C:10]([CH2:9][CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][C:3]([OH:21])=[O:2])=[O:20])[CH3:14])[CH:17]([CH3:19])[CH3:18]

Participants

Procedure

7-(1-Isobutoxy-ethoxycarbamoyl)-heptanoic acid methyl ester (36.6 g, 12.1 mmol, 1.0 eq) was stirred in THF (200 mL) and water (200 mL) in the presence of lithium hydroxide (8.68 g, 36.2 mmol, 3.0 eq) for 3 h at 50° C. THF was evaporated under vacuum and to the mixture water (100 mL) and ethyl acetate (200 mL) were added. The mixture was acidified cautiously to pH 3 by addition of 1N HCl. The organic phase was isolated and the aqueous layer re-extracted with ethyl acetate (150 mL). The organic phases were combined, dried (MgSO4), filtered and concentrated in vacuo. The product was obtained as a white solid (29.0 g, 83% yield), m/z 288 [M++H]+ and used in stage 4 without further purification.