(NE,S)-N-[(2-cyclopropylsulfanyl-5-nitrophenyl)methylidene]-2-methylpropane-2-sulfinamide → (S)-N-(1-(2-(Cyclopropylthio)-5-nitrophenyl)allyl)-2-methylpropane-2-sulfinamide

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Reaction Conditions

Reaction Steps

To 85A (3.0 g, 9.2 mmol) in THF (30 mL) and methyl tert-butylether (50 mL) at −78° C. was added vinylmagnesium bromide (1.0 M in THF, 20 mL, 20 mmol) dropwise. The mixture was stirred at −78° C. for 1.0 h before it was quenched with sat. NH4Cl (50 mL) at −78° C. The mixture was extracted with EtOAc (3×50 mL), the organic layer was washed with brine and dried over Na2SO4. After removal of solvent, the crude was purified by silica gel column chromatography using gradient EtOAc in hexanes to give 85B (2.45 g, 78% yield). HPLC and 1H NMR indicated 85B is a mixture of two diastereoisomers in a ratio of 5:1. Major isomer: 1H NMR (400 MHz, CDCl3) δ ppm 0.70-0.81 (m, 2H) 1.17-1.24 (m, 2H) 1.26 (s, 9H) 2.17 (m, 1H) 3.53 (d, J=2.64 Hz, 1H) 5.21-5.32 (m, 3H) 5.91 (m, 1H) 7.72 (d, J=8.79 Hz, 1H) 8.09 (dd, J=8.79, 2.64 Hz, 1H) 8.26 (d, J=2.64 Hz, 1H), LC-MS 355 (M+H).

Provenance & Evidence