Potassium Hydroxide → (2S,3S)-3-(ethoxycarbonyl)oxirane-2-carboxylic acid
反応式
[OH-].[K+].[O:3]1[C@H:5]([C:6]([O:8]CC)=[O:7])[C@H:4]1[C:11]([O:13][CH2:14][CH3:15])=[O:12]>CCO>[CH2:14]([O:13][C:11]([C@H:4]1[O:3][C@@H:5]1[C:6]([OH:8])=[O:7])=[O:12])[CH3:15]参加物
4
実験手順
An ethanolic solution of KOH (4.2 g, 64 mmol, in EtOH [50 ml]) was added dropwise to the 3a (9.7 g, 63 mmol) in EtOH (20 ml) at 0° C. for 30 min, and then the reaction was continued at r.t. for 8 h. The resulting viscous solution was diluted with ice water (150 ml), extracted with EA (2×200 ml). The aqueous layer was acidified with 1N HCl to pH˜4, and extracted with EA (3×150 ml). Combined organic extracts washed with brine (2×50 ml), dried over Na2SO4, and concentrated to afford the pure epoxide monoester 4 as colorless oil (8.9 g, 86.9%). 1H NMR (CDCl3, 400 MHz): δ 7.57 (br, 1H); 4.35-4.24 (m, 2H); 3.73 (s, 1H); 3.72 (s, 1H); 1.36-1.32 (t, 3H). 13C NMR (CDCl3, 100 MHz): 171.61, 166.40, 62.45, 52.20, 51.45, 13.89.