Dimethyl Sulfide → 1-Ethyl-4-(5-hexenyl)-2-oxocyclohexaneacetic Acid Methyl Ester

HRID 477052Notes

Reaction equation

HRID 477052 reaction equation
[CH3:1][O:2][C:3](=[O:14])[CH2:4][C:5]1([CH2:12][CH3:13])[CH2:10][CH2:9][CH:8]=[CH:7][C:6]1=[O:11].S(C)C>O1CCCC1>[CH3:1][O:2][C:3](=[O:14])[CH2:4][C:5]1([CH2:12][CH3:13])[CH2:10][CH2:9][CH:8]([CH2:8][CH2:7][CH2:6][CH2:5][CH:4]=[CH2:3])[CH2:7][C:6]1=[O:11]

Participants

4

Reactant 2

HCID 1068Dimethyl Sulfide2×HCID 136492416-Carbomethoxymethyl-6-ethyl-2-cyclohexen-1-one

Product 1

HCID 146499081-Ethyl-4-(5-hexenyl)-2-oxocyclohexaneacetic Acid Methyl EsterYield 165.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of 1-ethyl-2-oxocyclohex-3-eneacetic acid methyl ester (25 g, 127.6 mmol), CuBr.Me2S (2.62 g, 12.8 mmol) and Me2S (25.5 mL) in 375 mL of tetrahydrofuran was cooled to -40° C. under nitrogen and treated dropwise with H2C=CHCH2CH2CH2CH2MgBr (166.6 mmol, 303 mL of a 0.55M solution in tetrahydrofuran). Fifteen minutes after the addition, the reaction mixture was quenched with 300 mL of 1M HCl and extracted with 4×120 mL of ether. Drying (MgSO4), concentration in vacuo and flash chromatography (114 mm diameter column, 10% ethyl acetate in petroleum ether eluent) afforded the oily product (29.51 g, 105.4 mmol, 83%) as a mixture of diastereomers. A portion of the diastereomers was separated by preparative HPLC affording 2.25 g of isomer A, the higher Rf material, as a yellow oil.

Workup

  1. additionFifteen minutes after the addition
  2. customthe reaction mixture was quenched with 300 mL of 1M HCl
  3. extractionextracted with 4×120 mL of ether
  4. customDrying
  5. concentration(MgSO4), concentration in vacuo and flash chromatography (114 mm diameter column, 10% ethyl acetate in petroleum ether eluent)

Sources & evidence

ORD record
ord-da68fa4d7a6a4235be978254402d91db
Source dataset
uspto-grants-1989_12
Patent number
US04886826

Reaction notes

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