tert-Butyl bromoacetate → (4R,5S)-3[(2S)-3t-butoxycarbonyl-2-benzylpropionyl]-4-methyl-5-phenyl-oxazolidine-2-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of the resultant compound from Example 65 (12.9 g, 41.7 mmol) in dry THF (100 ml) under nitrogen was added at -78° C. a solution of sodium hexamethyldisilylamide 45.9 ml (1M in THF). After 30 min, t-butyl bromoacetate (13.6 ml, 83.4 mmol) was added as a solution in THF. The resulting reaction mixture was stirred for 1 h at -78° C., quenched with sat. NH4Cl solution (50 ml) and the entire reaction mixture partitioned between diethyl ether and water. The organic layer was separated and the aqueous layer extracted once with ether. The combined organic solutions were washed with 10% HCl, sat. NaHC3O, brine, dried (Na2SO4). filtered, and concentrated. The resulting yellow oil was submitted to silica gel chromatography (flash): yield 12.4 g (70%).

Provenance & Evidence