p-Toluenesulfonic acid → (S)-2,2-Dimethyl-3-(1-oxoheptyl)-4-oxazolidinecarboxylic Acid Methyl Ester

HRID 52250Notes

Reaction equation

HRID 52250 reaction equation
[CH3:1][O:2][C:3](=[O:16])[C@H:4]([CH2:14][OH:15])[NH:5][C:6](=[O:13])[CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH3:12].[CH3:17][C:18]1C=CC(S(O)(=O)=O)=C[CH:23]=1.C([O-])([O-])=O.[K+].[K+].CCCCCC.CCOC(C)=O>CC(C)=O.COC(OC)(C)C>[CH3:1][O:2][C:3]([C@@H:4]1[CH2:14][O:15][C:18]([CH3:23])([CH3:17])[N:5]1[C:6](=[O:13])[CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH3:12])=[O:16]

Participants

7

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 11430Potassium CarbonateHCID 21226206Ethyl acetate hexaneHCID 54165626HCID 54165626, compound

Product 1

HCID 53934458(S)-2,2-Dimethyl-3-(1-oxoheptyl)-4-oxazolidinecarboxylic Acid Methyl Ester

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 64952,2-DimethoxypropaneSolvent

Procedure

Compound 2j (320 mg, 1.38 mol) and p-TSA (40 mg) are dissolved in dry acetone (2 ml) and 2,2-dimethoxypropane (2 ml). The resulting solution is heated overnight at reflux. Solid K2CO3 is added and the volatiles removed in vacuo to give a residue. Flash chromatography (2×21 cm column, 6:1 hexane/EtOAc) of the residue provides 8a as an oil: NMR δ0.88 (m, 3H), 1.29 (m, 6H), 1.57 (s, 3H), 1.62 (m, 2H), 1.70 (s, 3H), 2.15 (m, 2H), 3.81 (s, 3H), 4.20 (m, 2H), 4.46 (m, 1H); [α]D26 =-47±1 (CHCl3).

Workup

  1. temperatureThe resulting solution is heated overnight
  2. temperatureat reflux
  3. customthe volatiles removed in vacuo
  4. customto give a residue

Sources & evidence

ORD record
ord-7ed3e970104f4be585c591d12c22c49b
Source dataset
uspto-grants-1997_04
Patent number
US05616612

Reaction notes

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