Ethyl 4-pentenoate → HCID 20775747, compound

HRID 1015645Notes

Reaction equation

HRID 1015645 reaction equation
[Li+].CC([N-][CH:6]([CH3:8])[CH3:7])C.[CH2:9]([O:11][C:12](=[O:17])[CH2:13][CH2:14][CH:15]=[CH2:16])[CH3:10].Br[CH2:19]C(C)=C>C1COCC1>[CH2:9]([O:11][C:12](=[O:17])[CH:13]([CH2:8][CH:6]=[CH2:7])[CH2:14][C:15]([CH3:19])=[CH2:16])[CH3:10]

Participants

5

Reactant 3

HCID 74786Ethyl 4-pentenoateHCID 3577853-Bromo-2-methyl-1-propeneHCID 2724682Lithium diisopropylamide

Product 1

HCID 20775747HCID 20775747, compoundYield 102%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a cold (−78° C.) stirred solution of LDA (generated from DIPA (1.42 mL, 10.14 mmol), BuLi (5.85 mL, 9.36 mmol) in THF at −78° C. for 20 min) in THF (31 mL) was added a solution of Pent-4-enoic acid ethyl ester (1.0 g, 7.8 mmol, 1.2 eq.) in THF (9.0 mL). After stirred for 1 h, neat 3-Bromo-2-methyl-propene (2.03 g, 15.0 mmol, 1.51 mL) was added and slowly warmed up to room temperature for overnight. The reaction mixture was then quenched with saturated NH4Cl solution, extracted with ether, washed with brine and dried. Evaporation of the solution furnished the 2-Allyl-4-methyl-pent-4-enoic acid ethyl ester (1.45 g, 100%) as an oil which was used in the next step without purification. 1H NMR (400 MHz, CDCl3), 5.78-5.71 (m, 1H), 5.05 (d, J=18.6 Hz, 1H), 5.02 (d, J=9.4 Hz, 1H), 4.76 (brs, 1H), 4.70 (s, 1H), 4.11 (dq, J=7.2, 1.0 Hz, 2H), 2.66-2.13 (m, 5H), 1.72 (s, 3H), 1.23 (dt, J=7.2, 1.3 Hz, 3H).

Workup

  1. customThe reaction mixture was then quenched with saturated NH4Cl solution
  2. extractionextracted with ether
  3. washwashed with brine
  4. customdried
  5. customEvaporation of the solution

Sources & evidence

ORD record
ord-71e079c15fcc4a0cb1155460b184ef7b
Source dataset
uspto-grants-2011_07
Patent number
US07985769B2

Reaction notes

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