Tri-o-tolylphosphine → diisopropyl (2S,3R)-2-hydroxy-3-{(2E)-3-[4-(trifluoromethoxy)phenyl]-2-propenyl}butanedioate

Participants

Reaction Conditions

Reaction Steps

To a solution of diisopropyl (2R,3S)-2-allyl-3-hydroxybutanedioate (Intermediate 2a, 5.0 g; 19.4 mmol; 1.0 eq.), TEA (6.23 mL; 46.5 mmol; 2.4 eq.) in CH3CN (50.0 mL) was added 1-bromo-4-(trifluoromethoxy)benzene (5.13 g; 21.3 mmol; 1.1 eq.). To this solution was added a sonicated mixture of tri-o-tolylphosphine (0.59 g; 1.94 mmol; 0.10 eq.) and palladium(II) acetate (43.46 mg; 0.19 mmol; 0.01 eq.) in CH3CN (4 mL). The reaction was stirred at 80° C. for 14 h, cooled to RT and the solvents were evaporated (rotavap). The residue was taken up in EtOAc and washed with an aqueous saturated solution of NH4Cl, an aqueous saturated solution of NaHCO3 and then with an aqueous saturated solution of NaCl and dried over MgSO4. Evaporation of the solvent gave an oil. Purification by chromatography (SiO2, gradient from 10/90 EtOAc/c-hex to 100/0 EtOAc/c-hex in 30 min.) gave a colorless oil (6.98 g, 86.2%). M+(ESI): 419.2; M−(ESI): 417.0.

Provenance & Evidence