Reaction equation
C(NC(C)C)(C)C.C([Li])CCC.C[Si](C)(C)[CH2:15][C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17].[CH2:25]([CH:28]1[CH2:33][CH2:32][CH2:31][CH2:30][C:29]1=O)[CH:26]=[CH2:27]>C1COCC1>[CH2:25]([CH:28]1[CH2:33][CH2:32][CH2:31][CH2:30][C:29]1=[CH:15][C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH:26]=[CH2:27]Participants
Conditions
- Temperature
- -10 °C
Procedure
To a solution of diisopropylamine (6.60 mL, 46.6 mmol) in THF (200 mL) at −10° C., was added a solution 2.22M of n-butyllithium (20.4 mL, 44.4 mmol). The solution was stirred 15 min at −10° C., cooled down to −78° C. and tert-butyl 2-trimethylsilylacetate (9.7 mL, 44.4 mmol) in 1 mL of THF was added dropwise. The solution was stirred 15 min at −78° C., and 2-allylcyclohexanone (3.3 mL, 22.2 mmol) was added dropwise. The reaction mixture was stirred 1 h at −78° C. and 3 h at −25° C. It was then quenched with saturated NH4Cl, extracted with ethylacetate, washed with brine, dried and concentrated. Purification by flash chromatography (cyclohexane) gave tert-butyl 2-(2-allylcyclohexylidene)acetate (5.06 g, 96%) as a colorless liquid. 1H NMR (400 MHz, CDCl3) 5.62 (1H, m), 5.41 (1H, s), 4.89 (2H, m), 3.83 (1H, m), 2.16 (3H, m), 1.90 (1H, m), 1.73 (1H, m), 1.61 (1H, m), 1.47-1.22 (4H, m), 1.36 (9H, s).
Workup
- temperaturecooled down to −78° C.
- stirringThe solution was stirred 15 min at −78° C.
- stirringThe reaction mixture was stirred 1 h at −78° C. and 3 h at −25° C
- customIt was then quenched with saturated NH4Cl
- extractionextracted with ethylacetate
- washwashed with brine
- customdried
- concentrationconcentrated
- customPurification by flash chromatography (cyclohexane)
Sources & evidence
- ORD record
- ord-091f7d2857c04d44bc887d2f237662d5
- Source dataset
- uspto-grants-2015_09
- Patent number
- US09131688B2
Linked notes
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