tert-Butyl methyl ether → (1S)-2-Methyl-1-methylthiocarbonyloxypropyl 2-methylpropanoate

HRID 558056Notes

Reaction equation

HRID 558056 reaction equation
COC(C)(C)C.[CH3:7][CH:8]([CH3:20])[C:9]([O:11][CH:12]([O:16][C:17]([CH3:19])=[S:18])[CH:13]([CH3:15])[CH3:14])=[O:10]>O>[CH3:7][CH:8]([CH3:20])[C:9]([O:11][C@@H:12]([O:16][C:17]([CH3:19])=[S:18])[CH:13]([CH3:14])[CH3:15])=[O:10]

Participants

4

Reactant 2

HCID 15413tert-Butyl methyl etherHCID 866102712-Methyl-1-methylthiocarbonyloxypropyl 2-methylpropanoate

Product 1

HCID 86633031(1S)-2-Methyl-1-methylthiocarbonyloxypropyl 2-methylpropanoateYield 70%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 990 mL methyl-tert-butylether (MTBE) and 10 mL water was stirred until a clear solution was obtained (ca. 5 hrs). To this solution was added 2-methyl-1-methylthiocarbonyloxypropyl 2-methylpropanoate (2b) (50 g) and PLE/MPEG (50 mg/1 g, 7.5 g). The resulting suspension was stirred at room temperature. The reaction was monitored by 1H-NMR using a chiral solvating agent. After 1H-NMR showed only one enantiomer remained in the reaction mixture (ca. 48 hrs), the reaction was quenched by filtration through a pad of CELITE® 545. The supernatant was washed with water, aqueous sodium bicarbonate (NaHCO3) and brine, and dried over anhydrous sodium sulfate (Na2SO4). After rotary evaporation, the title compound (12) was obtained with 70% yield. The enantiomeric excess of the S-enantiomer was 100% e.e. as determined by chiral HPLC. 1H-NMR (CDCl3): δ 0.96 (d, J=6.8 Hz, 6H), 1.16 (d, J=6.8 Hz, 3H), 1.17 (d, J=6.8 Hz, 3H), 1.98-2.07 (m, 1H), 2.32 (s, 3H), 2.56 (septet, J=7.2 Hz, 1H), 6.67 (d, J=5.6 Hz, 1H) ppm. 1H-NMR with chiral solvating agent (R)-(−)-2,2,2-trifluoro-1-(9-anthryl)ethanol: δ 0.98 (d, J=6.8 Hz, 3H), 0.99 (d, J=6.8 Hz, 3H), 1.19 (d, J=7.2 Hz, 1.5H), 1.19 (d, J=6.8 Hz, 1.5H), 1.20 (d, J=6.8 Hz, 1.5H), 1.20 (d, J=7.2 Hz, 1.5H), 2.01-2.09 (m, 1H), 2.34 1(s, 1.5H), 2.44 (s, 1.5H), 2.59 (septet, J=7.2 Hz, 0.5H), 2.59 (septet, J=6.8 Hz, 0.5H), 6.70 (d, J=5.6 Hz, 0.5H), 6.70 (d, J=5.2 Hz, 0.5H) ppm.

Workup

  1. customwas obtained (ca. 5 hrs)
  2. stirringThe resulting suspension was stirred at room temperature
  3. customremained in the reaction mixture (ca. 48 hrs)
  4. customthe reaction was quenched by filtration through a pad of CELITE® 545
  5. washThe supernatant was washed with water, aqueous sodium bicarbonate (NaHCO3) and brine
  6. dry with materialdried over anhydrous sodium sulfate (Na2SO4)
  7. customAfter rotary evaporation

Sources & evidence

ORD record
ord-b19116388a4b447da217e8e5f7857c8c
Source dataset
uspto-grants-2011_11
Patent number
US08062870B2

Reaction notes

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