tert-Butyl {4-[(2R,3R)-1-(4-chlorophenyl)-3-({[2-(4-chlorophenyl)-5,5-dimethyl-1,3-dioxan-2-yl]methyl}thio)-4-oxoazetidin-2-yl]phenoxy}acetate → [4-((2R,3R)-1-(4-Chlorophenyl)-3-{[2-(4-chlorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetic acid

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Reaction Steps

tert-Butyl {4-[(2R,3R)-1-(4-chlorophenyl)-3-({[2-(4-chlorophenyl)-5,5-dimethyl-1,3-dioxan-2-yl]methyl}thio)-4-oxoazetidin-2-yl]phenoxy}acetate (1.69 g, 2.57 mmol) was dissolved in formic acid (25 ml) and stirred for two hours. The mixture was concentrated under reduced pressure (temperature <30° C.) and the crude oil was purified by flash-chromatography (hexane:acetone:formic acid 60:40:0.1) to afford 1.08 g (81%) of the title compound as a pale yellow solid. 1H-NMR (CDCl3, 200 MHz): δ 4.0-4.2 (m, 3H), 4.7 (s, 2H), 4.9 (d, 1H), 6.9 (d, 2H), 7.2-7.4 (m, 6H), 7.5 (d, 2H), 7.9 (d, 2H). MS (CI) M/z: 514.2 (NT), 515.2 (30), 516.1 (70), 517.2 (20).

Provenance & Evidence