Tetrahydrofuran → 7,8-Dimethyl-4,4a,5,6-tetrahydro-2(3H)-naphthalenone

HRID 478071Notes

Reaction equation

C([N-][CH:5]([CH3:7])[CH3:6])(C)C.[Li+].C[C:10]1[C:11](=[O:17])[CH2:12][CH2:13][CH2:14][C:15]=1[CH3:16].[CH2:18]1COC[CH2:19]1>>[CH3:18][C:19]1[CH2:16][CH2:15][CH:14]2[C:7]([C:5]=1[CH3:6])=[CH:10][C:11](=[O:17])[CH2:12][CH2:13]2

Participants

Reactant 3

HCID 8028Tetrahydrofuran2×

HCID 2724682Lithium diisopropylamide

HCID 108878982,3-Dimethyl-2-cyclohexen-1-one

Product 1

HCID 124539797,8-Dimethyl-4,4a,5,6-tetrahydro-2(3H)-naphthalenoneYield 60%

Conditions

Temperature: 25 °C

Procedure

To a stirred solution of lithium diisopropylamide (LDA) (22 mmol) in THF (200 ml) at -78° C. was added a solution of 2,3-dimethylcyclohexenone (2.48 g, 20 mmol) in THF (50 ml). The mixture was warmed to 25° C., and the solvent and the amine were removed under vacuum. The resulting solid was dissolved in THF (400 ml) and the solution cooled to -78° C. To this solution was added MVK (1.8 ml, 22 mmol) in THF (100 ml) over 10 min. The resulting mixture was stirred 12 hr at room temperature, then worked up. Removal of solvent yielded the dione as a yellow oil (2.8 g, 60%).

Workup

customthe solvent and the amine were removed under vacuum
dissolutionThe resulting solid was dissolved in THF (400 ml)
temperaturethe solution cooled to -78° C
additionTo this solution was added MVK (1.8 ml, 22 mmol) in THF (100 ml) over 10 min
customRemoval of solvent

Sources & evidence

ORD record: ord-bbeec7b147a04622b97ec50f66b5c626
Source dataset: uspto-grants-1989_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04889947

Reaction notes

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