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

HRID 218415Notes

Reaction equation

[OH:1][CH2:2][C@@H:3]([NH:11][C:12](=[O:18])[O:13][C:14]([CH3:17])([CH3:16])[CH3:15])[CH2:4][C@H:5]([CH2:9][OH:10])[CH2:6][CH:7]=[CH2:8].[CH3:19][C:20]1C=CC(S(O)(=O)=O)=C[CH:25]=1.COC(OC)(C)C>CC(C)=O>[OH:10][CH2:9][C@H:5]([CH2:6][CH:7]=[CH2:8])[CH2:4][C@H:3]1[CH2:2][O:1][C:20]([CH3:25])([CH3:19])[N:11]1[C:12]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:18]

Participants

Conditions

Temperature: -20 °C

Procedure

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.

Workup

temperatureto warm to rt for 1 hr
stirringstirred for another 5 min
customThe solvent was removed under reduced pressure
dissolutionThe residue was dissolved in Et2O (300 mL)
washwashed with 1 N HCl (80 mL), sat. aq. NaHCO3 (80 mL), brine (80 mL) successively
customdried
filtrationfiltered
concentrationconcentrated under vacuum

Sources & evidence

ORD record: ord-b4cdf6785ec048cf934c0574eef45144
Source dataset: uspto-grants-2012_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08198453B2

Reaction notes

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