Acetylene → Ethyl Penta-2,4-dienoate

HRID 1603269Notes

Reaction equation

HRID 1603269 reaction equation
[CH2:1]([O:3][C:4](=[O:16])/[CH:5]=[C:6](\C)/[CH:7]=[CH:8]/C1CCCC=1Br)[CH3:2].P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.N1CCCCC1.C(C1C(C)(C)CCCC=1C)#C.C#C>C1C=CC=CC=1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[Cu]I>[CH2:1]([O:3][C:4](=[O:16])[CH:5]=[CH:6][CH:7]=[CH2:8])[CH3:2]

Participants

9

Reactant 5

HCID 6326AcetyleneHCID 8082PiperidineHCID 11776TriphenylphosphineHCID 132969122-Ethynyl-1,3,3-trimethylcyclohex-1-eneHCID 86753065(2E,4E)-5-(2-bromo-cyclopent-1-enyl)-3-methyl-penta-2,4-dienoic acid ethyl ester

Product 1

HCID 3806798Ethyl Penta-2,4-dienoate

Reagents, catalysts & solvents 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 178418397HCID 178418397, compoundCatalystHCID 241BenzeneSolvent2×

Procedure

(2E,4E)-5-(2-Bromo-cyclopent-1-enyl)3-methyl-penta-2,4-dienoic acid ethyl ester (1.43 g) was dissolved in 5 ml of benzene. At ambient temperature was added successively: 293 mg of Pd(Ph3P)4, 95 mg of CuI, 147 mg of (Ph)3P, and 8 ml of piperidine. To this mixture was added via dropping funnel within 1 hour 2-ethynyl-1,3,3-trimethyl-1-cyclohexene (745 mg) dissolved in 5 ml of benzene. After 4.5 hours, additional acetylene (350 mg) was added and stirring continued for 30 minutes. The mixture was then poured into crushed ice/HCI, extracted with EtOEt, washed twice with water, dried over Na2SO4, and evaporated to dryness. Medium pressure chromatography (SiO2, hexane/AcOEt=98/2) yielded 1.478 g of (2E, 4E)-3-Methyl-5-(2,6,6-trimethyl-cyclohex-1-enylethynyl)-cyclopent-1-enyl]-penta-2,4-dienoic acid ethyl ester as a yellow oil.

Workup

  1. additionAt ambient temperature was added successively
  2. additionTo this mixture was added
  3. customwithin 1 hour
  4. waitcontinued for 30 minutes
  5. additionThe mixture was then poured
  6. custominto crushed ice/HCI
  7. extractionextracted with EtOEt
  8. washwashed twice with water
  9. dry with materialdried over Na2SO4
  10. customevaporated to dryness

Sources & evidence

ORD record
ord-d976a89524fe466ab689ea69fba5abcc
Source dataset
uspto-grants-1999_11
Patent number
US05986131

Reaction notes

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