Carbon Dioxide → Benzyl 3-phenylpropionate Carbonate

Participants

Reaction Steps

(S)-Benzyl 2-hydroxy-3-phenylpropionate (1.54 g, 6 mmol, 3 eq) is dissolved in anhydrous N,N-dimethylforamide (20 mL) to make a clear solution. Into the solution, are consecutively added cesium carbonate (1.95 g, 6 mmol) and tetrabutylammonium iodide (2.22 g, 6 mmol, 3 eq). The suspension is stirred at room temperature while passing carbon dioxide gas through for 1 hour before Merrifield's peptide resin (1 g, 2 mmol) is added to the to solution. Carbon dioxide gas continuously bubbles through the solution and the reaction is allowed to proceed overnight at 60° C. The mixture is then cooled to room temperature, and diluted with water. The resin is washed successively with MeOH/H2O, H2O, 0.2 N HCl, H2O, THF, CH2Cl2, and MeOH. After drying under vacuum, 1.33 g of resin is obtained (63% yield): IR3071, 3035, 2921, 2846, 1943, 1874, 1611, 1495, 1462, 1394, 1253, 1172, 1036, 765, 700 cm−1.

Provenance & Evidence