p-Toluenesulfonic acid → (S)-tert-Butyl 4-((R)-2-(hydroxymethyl)pent-4-en-1-yl)-2,2-dimethyloxazolidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl (2S,4R)-1-hydroxy-4-(hydroxymethyl)hept-6-en-2-ylcarbamate (6.8 g, 26.2 mmol) in acetone (150 mL), PTSA (0.45 g, 2.62 mmol) was added. The reaction mixture was cooled to −20° C. followed by the addition of 2,2-dimethoxypropane (4.1 g, 39.4 mmol). The resulting mixture was stirred and allowed to warm to rt for 1 hr. TEA (0.5 mL) was then added and stirred for another 5 min. The solvent was removed under reduced pressure. The residue was dissolved in Et2O (300 mL), washed with 1 N HCl (80 mL), sat. aq. NaHCO3 (80 mL), brine (80 mL) successively, and dried, filtered, and concentrated under vacuum to give crude (S)-tert-butyl 4-((R)-2-(hydroxymethyl)pent-4-enyl)-2,2-dimethyloxazolidine-3-carboxylate (7.5 g, 96%). It was used without further purification.

Provenance & Evidence