Ethyl Acetate → trans-1-Chloro-3-methyl-5-(2,6,6-trimethyl-cyclohex-1-enyl)-pent-1-en-4-yn-3-ol

HRID 1831879Notes

Reaction equation

HRID 1831879 reaction equation
[C:1]([C:3]1[C:8]([CH3:10])([CH3:9])[CH2:7][CH2:6][CH2:5][C:4]=1[CH3:11])#[CH:2].C([Li])CCC.[Cl:17][CH:18]=[CH:19][C:20](=[O:22])[CH3:21].C(OCC)(=O)C>O1CCCC1.CCCCCC>[Cl:17]/[CH:18]=[CH:19]/[C:20]([CH3:21])([OH:22])[C:2]#[C:1][C:3]1[C:8]([CH3:10])([CH3:9])[CH2:7][CH2:6][CH2:5][C:4]=1[CH3:11]

Participants

7

Reactant 4

HCID 8857Ethyl AcetateHCID 132969122-Ethynyl-1,3,3-trimethylcyclohex-1-eneHCID 534274284-Chloro-buten-2-oneHCID 178418339Butyllithium

Product 1

HCID 22052823trans-1-Chloro-3-methyl-5-(2,6,6-trimethyl-cyclohex-1-enyl)-pent-1-en-4-yn-3-olYield 47%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent2×

Conditions

Temperature
-65 °C

Procedure

A solution of 1.48 g (10 mmol) of 2-ethynyl-1,3,3-trimethyl-cyclohexene in 90 ml of dry tetrahydrofuran in a 250 ml three-necked reaction flask equipped with a magnetic stirrer, a rubber septum and argon gasification means was cooled under an argon atmosphere in a dry ice bath. It was treated dropwise with 7.5 ml (12 mmol) of a 1.6 M solution of n-butyllithium in hexane as fast as the temperature could be maintained at −70 to −60° C. The addition was completed within 10 minutes. After the reaction mixture had been stirred for an additional 30 minutes at −70° C., a solution of 1.045 g (10 mmol) of 4-chloro-buten-2-one in 10 ml of dry tetrahydrofuran was added slowly. After further stirring for 3 hours at −70° C. the reaction mixture was poured into 250 ml of ice water and extracted with three 70 ml quantities of hexane. The combined organic phases were washed with three 100 ml quantities of water and 50 ml of brine, and dried over anhydrous magnesium sulphate. All the volatile material was removed under a reduced pressure of 100–200 mbar (10–20 kPa), and 2.57 g of crude product were obtained. Chromatography through 60 of silica gel (0.04–0.063 mm) with a 95:5 (v/v) mixture of hexane and ethyl acetate afforded 1.19 g (4.7 mmol, 47% yield) of the pure product.

Workup

  1. temperaturea rubber septum and argon gasification means was cooled under an argon atmosphere in a dry ice bath
  2. additionThe addition
  3. stirringAfter further stirring for 3 hours at −70° C. the reaction mixture
  4. extractionextracted with three 70 ml quantities of hexane
  5. washThe combined organic phases were washed with three 100 ml quantities of water and 50 ml of brine
  6. dry with materialdried over anhydrous magnesium sulphate
  7. customAll the volatile material was removed under a reduced pressure of 100–200 mbar (10–20 kPa)
  8. custom2.57 g of crude product were obtained

Sources & evidence

ORD record
ord-506f84ae5fb0444aba492fc0087844c3
Source dataset
uspto-grants-2006_06
Patent number
US07067703B2

Reaction notes

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