Diisopropylethylamine → (R)-tert-butyl 4-((1R,2R)-3-((R)-4-benzyl-2-oxooxazolidin-3-yl)-1-hydroxy-2-methyl-3-oxopropyl)-2,2-dimethyloxazolidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-3-(1-oxopropyl)-4-benzyl-2-oxazolidinone (Aldrich, 2.0 g, 8.6 mmol) in DCM (60 mL) at −40° C., a solution of TiCl4 in DCM (1.0 M, 10.0 mL, 10.0 mmol) was added. The mixture was stirred at −40° C. for 10 min., then DIPEA (3.7 mL, 21 mmol) was added. The reaction mixture was allowed to warm to 0° C. and stirred for 20 min. A solution of tert-butyl (4R)-4-formyl-2,2-dimethyl-1,3-oxazolidine-3-carboxylate (Aldrich, 2.0 g, 8.7 mmol) in DCM (20 mL) was then added dropwise and the resulting mixture was stirred for 1.5 h. The reaction was quenched by the addition of a saturated aq. NH4Cl and the mixture was extracted with EtOAc. The separated organic phase was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (eluting with 0-40% EtOAc in hexanes) to give the sub-title compound as the major product (5:2) in 87% yield (3.44 g). LCMS calc. for C24H34N2NaO7 (M+Na)+: m/z=485.2. found 485.1.

Provenance & Evidence