Diisopropylamine → Ethyl 2-benzyl-2-methyl-5-trimethylsilylpent-4-ynoate
Reaction equation
C(NC(C)C)(C)C.C([Li])CCC.[C:13]1([CH2:19][CH:20]([CH3:26])[C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[CH3:27][Si:28]([CH:31](Br)[C:32]#[CH:33])([CH3:30])[CH3:29]>O1CCCC1>[CH2:19]([C:20]([CH3:26])([CH2:33][C:32]#[C:31][Si:28]([CH3:30])([CH3:29])[CH3:27])[C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1Participants
Conditions
- Temperature
- 0 °C
Procedure
To a solution of 2.2 ml (1.58 gm) of diisopropylamine in 20 ml of dry tetrahydrofuran, was added dropwise a solution of n-butyllithium (9.7 ml, 1.6M) at 0° C. The solution was stirred at 0° C. for 30 min, then cooled to -78° C. A solution of 2.5 gm of ethyl 3-phenyl-2-methylpropionate in 10 ml of dry tetrahydrofuran was added. After 30 min., 3 gm of trimethylsilylpropargyl bromide in 10 ml dry tetrahydrofuran was added. The mixture was warmed up to 0° C. slowly and maintained at 0° C. for 1.75 hours. The reaction mixture was quenched with 5% hydrochloric acid and partitioned between ether and 5% hydrochloric acid. The ethereal layer, washed with brine solution and water was dried and evaporated in an oil. The oil was chromatographed on silica gel (5% ethyl acetate; petroleum ether). This procedure yielded the title compound, IR: 2170, 1738 cm-1.
Workup
- temperaturecooled to -78° C
- waitAfter 30 min.
- temperatureThe mixture was warmed up to 0° C. slowly
- temperaturemaintained at 0° C. for 1.75 hours
- customThe reaction mixture was quenched with 5% hydrochloric acid
- custompartitioned between ether and 5% hydrochloric acid
- washThe ethereal layer, washed with brine solution and water
- customwas dried
- customevaporated in an oil
- customThe oil was chromatographed on silica gel (5% ethyl acetate; petroleum ether)
Sources & evidence
- ORD record
- ord-91e8f8f18a554fdb8f08952ce285843e
- Source dataset
- uspto-grants-1986_07
- Patent number
- US04602006
Reaction notes
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