Hydrochloric Acid → tert-butyl (1S,2R)-1-fluoro-1-phenylbut-3-en-2-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a 150 mL RBF containing (R)—N-((1S,2R)-1-fluoro-1-phenylbut-3-en-2-yl)-2-methylpropane-2-sulfinamide (107.00 mg, 397 μmol) was added methanol (5 mL) and the mixture was allowed to stir at 0° C. for 10 min. At this time, HCl (4N) (993 μl, 3972 μmol) was added and the reaction was allowed to stir for 30 min. Then TEA (1384 μl, 9930 μmol) was added to the mixture followed by DCM (2 ml) and BOC2O (173 mg, 794 μmol) in one portion. The reaction was allowed to stir overnight and then the bulk of the methanol was removed by evaporation. The residue was dissolved in EtOAc and washed with HCL (0.5 N, 2×40 ml). The combined aqueous layers were back extacted with EtOAc. The combined organics were washed with sodium bicarbonate (1×50 ml, sat) and brine and then dried with sodium sulfate. The dried solution was passed though a plug of silica gel to give tert-butyl (1S,2R)-1-fluoro-1-phenylbut-3-en-2-ylcarbamate (111.0 mg). Rf=0.45 in 20% EtOAc in hexanes, UV active and stain yellow to anisaldehyde. LC/MS give an ionization for eliminated product (mass=190).

Provenance & Evidence