7-(3-Hydroxy-5-oxo-1-cyclopentenyl)-heptanoic acid ethyl ester → 4-Tert-butoxy-2-(6-carbethoxyhexyl)cyclopent-2-en-1-one

HRID 461261Notes

Reaction equation

HRID 461261 reaction equation
BrC1C[C:5](=O)[C:4]([CH2:8]CCCCCC(OCC)=O)=[CH:3]1.[OH:19][CH:20]1[CH2:24][C:23](=[O:25])[C:22]([CH2:26][CH2:27][CH2:28][CH2:29][CH2:30][CH2:31][C:32]([O:34][CH2:35][CH3:36])=[O:33])=[CH:21]1>C(=O)([O-])[O-].[Ag+2].C(O)(C)(C)C>[C:4]([O:19][CH:20]1[CH2:24][C:23](=[O:25])[C:22]([CH2:26][CH2:27][CH2:28][CH2:29][CH2:30][CH2:31][C:32]([O:34][CH2:35][CH3:36])=[O:33])=[CH:21]1)([CH3:8])([CH3:5])[CH3:3]

Participants

5

Reactant 2

HCID 98379417-(3-Hydroxy-5-oxo-1-cyclopentenyl)-heptanoic acid ethyl esterHCID 204655494-Bromo-2-(carbethoxyhexyl)cyclopent-2-en-1-one

Product 1

HCID 233299924-Tert-butoxy-2-(6-carbethoxyhexyl)cyclopent-2-en-1-one

Reagents, catalysts & solvents 2

HCID 178418647HCID 178418647, compoundCatalystHCID 6386tert-ButanolSolvent

Procedure

A stirred mixture of 6.35 g. (20 mmoles) of 4-bromo-2-(carbethoxyhexyl)cyclopent-2-en-1-one (Example 94), 3.01 g. (11 moles) of silver carbonate, and 40 ml. of t-butanol is heated at 70° C. for 17 hours. The mixture is cooled and filtered. After evaporation of t-butanol the residue is treated with aq. sodium chloride and extracted with 3:1 ether-hexane. The extract is washed with saturated sodium chloride solution, dried over magnesium sulfate, and concentrated. The crude product is purified by chromatography on silica gel to give, in order of elution: the subject compound as an oil; λ maxMeOH. = 219 mμ (8860); ν max. = 1735 (ester carbonyl group), 1725 ketone carbonyl group), and 1365 cm-1 (tert.-butyl group); and 4-hydroxy-2-(6-carbethoxyhexyl)cyclopent-2-en-1-one also as an oil.

Workup

  1. additionA stirred mixture of 6.35 g
  2. temperatureThe mixture is cooled
  3. filtrationfiltered
  4. customAfter evaporation of t-butanol the residue
  5. additionis treated with aq. sodium chloride
  6. extractionextracted with 3:1 ether-hexane
  7. washThe extract is washed with saturated sodium chloride solution
  8. dry with materialdried over magnesium sulfate
  9. concentrationconcentrated
  10. customThe crude product is purified by chromatography on silica gel
  11. customto give, in order of elution

Sources & evidence

ORD record
ord-73659dede16640cd988d84e9e7c565bb
Source dataset
uspto-grants-1977_12
Patent number
US04061672

Reaction notes

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