Sodium Carbonate → 5-Methyl-3-oxocyclohex-1-en-1-yl trifluoromethanesulfonate

HRID 1920211Notes

Reaction equation

[CH3:1][CH:2]1[CH2:7][C:6](=[O:8])[CH2:5][C:4](=[O:9])[CH2:3]1.C([O-])([O-])=O.[Na+].[Na+].[O:16](S(C(F)(F)F)(=O)=O)[S:17]([C:20]([F:23])([F:22])[F:21])(=O)=[O:18]>C(Cl)Cl>[F:21][C:20]([F:23])([F:22])[S:17]([O:8][C:6]1[CH2:7][CH:2]([CH3:1])[CH2:3][C:4](=[O:9])[CH:5]=1)(=[O:18])=[O:16]

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 5-methylcyclohexane-1,3-dione (1 equiv) in DCM (0.4M) was added Na2CO3 (1.0 equiv.) and cooled to 0° C. Added Tf2O (1.0 equiv.) in DCM (5M) dropwise over 1 hr at 0° C. under a nitrogen atmosphere. Upon addition, the reaction was stirred for 2 hr at room temperature (dark red solution). The solution was filtered and to the filtrate was added saturated NaHCO3 (carefully), then extracted the organics, dried with brine, then Na2SO4, and concentrated. The crude was purified via SiO2 column chromatography eluting with DCM and hexanes (1:1) or alternatively via a neutral alumina plug eluting with DCM to afford 5-methyl-3-oxocyclohex-1-enyl trifluoromethanesulfonate in 30% or 67% yield respectively. The triflate decomposes upon storage and should be used immediately for the next reaction. LC/MS=259.1/300.1 (M+H and M+CH3CN); Rt=0.94 min, LC=3.84 min.

Workup

additionUpon addition
filtrationThe solution was filtered and to the filtrate
additionwas added saturated NaHCO3 (carefully),
extractionthen extracted the organics,
dry with materialdried with brine
concentrationNa2SO4, and concentrated
customThe crude was purified via SiO2 column chromatography
washeluting with DCM and hexanes (1:1) or alternatively via a neutral alumina plug
washeluting with DCM

Sources & evidence

ORD record: ord-ce7827a2868b4f0eab26c0e1c9047e72
Source dataset: uspto-grants-2012_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08168794B2

Reaction notes

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