Methyl (2Z)-2-[(tert-butoxycarbonyl)amino]-3-[4-(2-tert-butyl-1,1-dioxido-3-oxoisothiazolidin-5-yl)-3-fluorophenyl]acrylate → Methyl (2S)-2-[(tert-butoxycarbonyl)amino]-3-[4-(2-tert-butyl-1,1-dioxido-3-oxoisothiazolidin-5-yl)-3-fluorophenyl]propanoate

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Reaction Steps

Methyl (2Z)-2-[(tert-butoxycarbonyl)amino]-3-[4-(2-tert-butyl-1,1-dioxido-3-oxoisothiazolidin-5-yl)-3-fluorophenyl]acrylate (1.24 g, 2.56 mmol) in ethanol (100 mL) was degassed and (R,R)-(−)-1,2-bis[(o-methoxyphenyl)(phenyl)phosphino]ethane(1,5-cyclooctadiene) rhodium (I) tetrafluroborate (58 mg, 0.077 mmol) was added under nitrogen. The solution was placed under a hydrogen atmosphere (50 psi) and shaken for 16 h. The solution was concentrated in vacuo and purified by silica gel chromatography (10–40% ethyl aceate:hexanes) to afford product as a white foam (1.14 g, 92%). 1H NMR (400 MHz, CDCl3): δ 7.29–7.27 (m, 1H), 7.03–6.95 (m, 2H), 5.06–5.02 (m, 2H), 4.61–4.57 (brs, 1H), 3.73 (s, 3H), 3.31–3.27 (m, 1H), 3.15–3.06 (m, 3H), 1.66 (s, 9H), 1.42 (s, 9H). LCMS found for C22H32FN2NaO7S (M+Na)+: m/z=509.

Provenance & Evidence