Potassium Hydroxide → 3(R)-hydroxy-2-methylene-3-phenylpropanoic Acid

Reaktionsgleichung

[OH-].[K+].[OH:3][CH:4]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)[C:5](=[CH2:10])[C:6]([O:8]C)=[O:7]>O.CO>[OH:3][C@H:4]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)[C:5](=[CH2:10])[C:6]([OH:8])=[O:7]

Komponenten

Versuchsvorschrift

A solution of potassium hydroxide (2.65 g, 0.047 mol, 1.3 eq) in water (60 mL) was added drop wise to a solution of 1b (7 g, 0.036 mol, 1 eq) in methanol (20 mL) (see FIG. 5). The mixture was stirred at room temperature for 15 h. The solution was then concentrated under vacuum. The aqueous phase was washed with ether (2×100 mL), acidified with 6N aqueous HCl solution and extracted with ether (3×100 mL). The combined organic extracts were washed with brine (100 mL) and dried over sodium sulfate. Evaporation of the solvent afforded a colorless oil which crystallized upon standing. The desired product 9b was obtained as a solid (6.29 g, 97%). Rf 0.26 (hexane/EtOAc=6:4). 1H NMR δ (DMSO-d6) 5.41 (s, 1H), 5.61 (s, 1H), 5.93 (s, 1H), 6.15 (s, 1H), 7.22 (m, 5H), 12.45 (s, 1H). [M−H]− 177.1, tR=1.23 min; purity: 91%.