p-Toluenesulfonic acid → Methyl 7-[2-(2-hydroxy-2-methylheptylthio)-5-oxopyrrolidin-1-yl]-6-oxoheptanoate

HRID 371335Notes

Reaction equation

HRID 371335 reaction equation
O=[C:2]1[CH2:6][CH2:5][C:4](=[O:7])[N:3]1[CH2:8][C:9]([O:20]C)(OC)[CH2:10][CH2:11][CH2:12][CH2:13][C:14]([O:16][CH3:17])=[O:15].[BH4-].[Na+].[SH:24][CH2:25][C:26]([OH:33])([CH3:32])[CH2:27][CH2:28][CH2:29][CH2:30][CH3:31].CC1C=CC(S(O)(=O)=O)=CC=1>C(O)C.Cl.[Cl-].[Na+].C(Cl)Cl>[OH:33][C:26]([CH3:32])([CH2:27][CH2:28][CH2:29][CH2:30][CH3:31])[CH2:25][S:24][CH:2]1[CH2:6][CH2:5][C:4](=[O:7])[N:3]1[CH2:8][C:9](=[O:20])[CH2:10][CH2:11][CH2:12][CH2:13][C:14]([O:16][CH3:17])=[O:15]

Participants

9

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 4311764Sodium borohydrideHCID 135068602-Methyl-1-sulfanylheptan-2-OLHCID 20273771Methyl 7-(2-oxo-5-oxo-pyrrolidin-1-yl)-6,6-dimethoxy-1-heptanoate

Product 1

HCID 20273770Methyl 7-[2-(2-hydroxy-2-methylheptylthio)-5-oxopyrrolidin-1-yl]-6-oxoheptanoateYield 11.5%

Reagents, catalysts & solvents 4

HCID 313Hydrochloric AcidCatalystHCID 702EthanolSolventHCID 5234Sodium ChlorideSolventHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 15 (50 mg, 0.16 mmol) in ethanol (2 mL) at 0° was added sodium borohydride (10 mg, 0.25 mmol). Two drops of 2N hydrochloric acid (in ethanol) were added at fifteen minute intervals for 1.5 hours. After continued stirring at 0° for one hour, the reaction was diluted with saturated aqueous sodium chloride and extracted three times with chloroform. The combined chloroform layer was dried over sodium sulfate. Removal of the solvent afforded 57 mg of the crude product which was dissolved in 2 mL of methylene chloride and treated with 20 mg of 1-mercapto-2-hydroxy-2-methylheptane in the presence of 15 mg of PTSA at room temperature overnight. It was then diluted with methylene chloride and washed with saturated sodium chloride solution. The separated aqueous layer was extracted twice with methylene chloride and the combined organic layer was dried over magnesium sulfate. The crude product was purified by preparative TLC to give 5.7 mg of methyl 7-[2-(2-hydroxy-2-methylheptylthio)-5-oxopyrrolidin-1-yl]-6-oxoheptanoate (16). IR (CH2Cl2): 1740, 1705 cm-1 ; PMR (CDCl3): δ 4.87 (t, 1H), 4.23 (AB, q, 2H), 3.67 (s, 3H), 2.70-1.20 (m, 22H), 1.20 (s, 3H), and 0.90 (t, 3H); MS: m/z 240.1227 (M+ -lower side chain), calcd. for C12H18NO4, 240.1236.

Workup

  1. extractionextracted three times with chloroform
  2. dry with materialThe combined chloroform layer was dried over sodium sulfate
  3. customRemoval of the solvent
  4. customafforded 57 mg of the crude product which
  5. washwashed with saturated sodium chloride solution
  6. extractionThe separated aqueous layer was extracted twice with methylene chloride
  7. dry with materialthe combined organic layer was dried over magnesium sulfate
  8. customThe crude product was purified by preparative TLC

Sources & evidence

ORD record
ord-86c5dcb91ccc49618a53f95a2a1d1e8b
Source dataset
uspto-grants-1985_07
Patent number
US04530933

Reaction notes

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