Pyridine → (S)-tert-butyl 4-((R)-5-tert-butoxy-5-oxo-2-(tosyloxymethyl)pentyl)-2,2-dimethyloxazolidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-tert-butyl 4-((R)-5-tert-butoxy-2-(hydroxymethyl)-5-oxopentyl)-2,2-dimethyloxazolidine-3-carboxylate (244 mg, 0.63 mmol) in anhydrous DCM (6 mL) was added pyridine (2 mL) and catalytic amount of DMAP, the solution was chilled to 0° C. TsCl (360 mg, 1.88 mmol) was added and stirred at rt overnight. The reaction mixture was diluted with EtOAc (40 mL) and washed with 1 N HCl (two times, 50 ml+20 ml), followed by H2O, aq. NaHCO3, brine, dried over Na2SO4, and filtered. After evaporation, the residue was purified on silica gel column, eluted with 0-20% EtOAc in hexane to afford (S)-tert-butyl 4-((R)-5-tert-butoxy-5-oxo-2-(tosyloxymethyl)pentyl)-2,2-dimethyloxazolidine-3-carboxylate (317 mg, yield 93%). MS ESI +ve m/z 564 (M+Na).

Provenance & Evidence