Pivaloyl chloride → HCID 57991875, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (E)-4-(tert-butyldimethylsilyloxy)but-2-enoic acid (18.0 g, 83.6 mmol) (prepared as described in Angewandte Chemie, International Edition (2002), 41(9), 1603-1607) in 400 mL of THF was added TEA (13.2 mL, 95 mmol). The mixture was chilled to −78° C. Pivaloyl chloride (10.2 mL, 83 mmol) (commercially available from Aldrich, Milwaukee, Wis.) was added. After 10 minutes, the mixture was warmed to room temperature and stirred for 45 minutes. The mixture was then chilled to −78° C. In a separate flask, (S)-4-phenyloxazolidin-2-one (12.3 g, 79 mmol) was taken up in 125 mL of THF and chilled to −78° C. n-Butyllithium (32 mL, 2.5 M in hexanes)(commercially available from Acros Organics (Order Number 30385)) was added to the (S)-4-phenyloxazolidin-2-one mixture, and the mixture was stirred for 20 minutes. The metallated oxazolidinone was then cannulated into the pivaloyl anhydride mixture. The combined mixture was then warmed to 0° C. and stirred for 1 hour. The reaction was quenched with 250 mL of aq NH4Cl and diluted with 250 mL of water. The mixture was extracted with EtOAc (2×250 mL) and the combined organic extracts were washed with brine (150 mL) and dried over MgSO4. Filtration and concentration under reduced pressure afforded a yellow solid that was recrystallized from DCM/hexanes to afford (S,E)-3-(4-(tert-butyldimethylsilyloxy)but-2-enoyl)-4-phenyloxazolidin-2-one (17.8 g, 62%) as a white solid. 1H NMR (400 MHz, CDCl3): ppm 7.46 (dt, J=2.1, 15.1 Hz, 1H), 7.31-7.20 (m, 5H), 7.02 (dt, J=3.4, 15.3 Hz, 1H), 5.40 (dd, J=3.9, 8.6 Hz, 1H), 4.61 (t, J=8.8 Hz, 1H), 4.19 (dd, J=3.9 Hz, 8.8 Hz, 1H), 0.85 (s, 9H), 0.00 (s, 6H). 2H were obscured.

Provenance & Evidence