[OH:1][CH2:2][C@@H:3]([CH2:19][CH2:20][CH2:21][CH3:22])[C:4](N1[C@@H](CC2C=CC=CC=2)COC1=O)=[O:5].[OH:23]O.O.[OH-].[Li+]>C1COCC1.O.O>[OH:1][CH2:2][C@@H:3]([CH2:19][CH2:20][CH2:21][CH3:22])[C:4]([OH:5])=[O:23]To a 2000 mL roundbottom flask was added (4S)-3-[(2R)-2-(hydroxymethyl)hexanoyl]-4-(phenylmethyl)-1,3-oxazolidin-2-one (4) (82 g, 0.268 mol) in THF/water (4:1, 750 mL). The solution was cooled to 0° C. and H2O2 (130 mL, 1.07 mol) was added dropwise, followed by lithium hydroxide monohydrate (22.58 g, 0.537 mol) in water (130 mL). The reaction mixture was warmed up to rt and stirred overnight. THF was removed under vacuum, and the aqueous solution was washed with ethyl acetate. The aqueous solution was then acidified to pH ˜3.0 and extracted with ethyl acetate. The extracts were dried (Na2SO4), filtered and concentrated to provide the title compound (42 g, 107%). LCMS: (2M+H)+: 313.2.
読み込み中…
