3-Penten-2-one, 5-(2,2,3-trimethyl-3-cyclopenten-1-yl)- → 4-Penten-2-one, 5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-

HRID 2309674Notes

Reaction equation

HRID 2309674 reaction equation
[CH3:1][C:2]1([CH3:14])[C:6]([CH3:7])=[CH:5][CH2:4][CH:3]1[CH2:8][CH:9]=[CH:10][C:11](=[O:13])[CH3:12].CC(C)([O-])C.[K+]>COCCOC>[CH3:1][C:2]1([CH3:14])[C:6]([CH3:7])=[CH:5][CH2:4][CH:3]1[CH:8]=[CH:9][CH2:10][C:11](=[O:13])[CH3:12]

Participants

4

Reactant 2

HCID 1083563-Penten-2-one, 5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-HCID 23665647Potassium tert-butoxide

Product 1

HCID 1083574-Penten-2-one, 5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-Yield 66%

Reagents, catalysts & solvents 1

HCID 80711,2-DimethoxyethaneSolvent

Procedure

The ketone, 5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-3-en-2-one, which had been prepared by using the procedure of U.S. Pat. No. 4,052,341, Example II-2, was reacted essentially following the procedure described in Example I for isomerizing the α,β double bond to the β,γ position. In this case the ketone (28.8 g, 0.15 mole) was reacted with potassium t-butoxide (25.8 g, 0.23 mole) in 1,2-dimethoxyethane (DME) (125 ml). The reaction was quenched by addition of aqueous 20% acetic acid (115 ml), extracted as in Example I and the oil distilled at reduced pressure to yield 19.0 g (66% yield) of 5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-one as a mixture of Z- (21%) and E- (69%) isomers: bp 80°-100° C. (0.5 mm); mol. wt. 192 (MS); IR 3040 cm-1 (olefin), 1720 (carbonyl), 800 (trisubstituted olefin).

Workup

  1. customThe reaction was quenched by addition of aqueous 20% acetic acid (115 ml)
  2. extractionextracted as in Example I
  3. distillationthe oil distilled at reduced pressure

Sources & evidence

ORD record
ord-891b6243606a479799a0df9bb50fc279
Source dataset
uspto-grants-1987_09
Patent number
US04696766

Reaction notes

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