Diisopropylethylamine → HCID 57384180, compound

Participants

Reaction Conditions

Reaction Steps

Diisopropylethylamine (51 mL, 290 mmol) was added slowly to a mechanically stirred, 0° C. slurry composed of {2-[(4R)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]-2-oxoethyl}phosphonate (94.8 g, 267 mmol; see Shapiro, G; Chengzhi, C. Tetrahedron Lett. 1992, 33, 2447) and dry lithium chloride (12.5 g, 280 mmol) in acetonitrile (260 mL). After stirring for 10 min, a solution of 2-benzyloxyacetaldehyde (40.0 g, 267 mmol) in acetonitrile (20 mL) was added dropwise over 10 min. The cooling bath was then removed and the reaction mixture was stirred at rt for 12 h before being partitioned between ether and water and the layers separated The aqueous phase was extracted with additional ether and the combined organic phases (700 mL total) were stirred at rt with 2M HCl (350 mL) for 1 h. The organic phase was then washed with saturated NaCl and NaHCO3 aqueous solutions, followed by drying over a mixture of Na2SO4 and MgSO4, and concentration in vacuo. Flash chromatography of the residue on silica gel eluting with 10/90 acetone/benzene yielded (4R)-4-benzyl-3-[(2E)-4-(benzyloxy)but-2-enoyl]-1,3-oxazolidin-2-one as a colorless solid upon trituration with ether. 1H NMR (500 MHz, d6-acetone) δ 7.57 (1H, d, J= 15.6 Hz), 7.43-7.27 (10H, m), 7.21-7.15 (1H, m), 4.84 (1H, t, J= 8.2 Hz), 4.64 (2H, s), 4.43 (1H, t, J= 8.5 Hz), 4.32 (2H, m), 4.29 (1H, dd, J= 2.9, 8.9 Hz), 3.24 (1H, dd, J= 3.1, 13.5 Hz), 3.03 (1H, dd, J= 8.4, 13.5 Hz).

Provenance & Evidence