Methyl propiolate → Methyl 4-hydroxy-4-(2,3,4-trimethoxyphenyl)-2-butynoate
Reaction equation
[C:1]([O:5][CH3:6])(=[O:4])[C:2]#[CH:3].C([Li])CCC.[CH3:12][O:13][C:14]1[C:21]([O:22][CH3:23])=[C:20]([O:24][CH3:25])[CH:19]=[CH:18][C:15]=1[CH:16]=[O:17].[Cl-].[NH4+]>O1CCCC1>[OH:17][CH:16]([C:15]1[CH:18]=[CH:19][C:20]([O:24][CH3:25])=[C:21]([O:22][CH3:23])[C:14]=1[O:13][CH3:12])[C:3]#[C:2][C:1]([O:5][CH3:6])=[O:4]Participants
Procedure
A solution of 3.4 ml (40 mmol) of methyl propiolate in 30 ml of tetrahydrofuran was treated at -78° under argon with 25 ml of n-butyllithium (1.6M in hexane). The mixture was stirred at -78° for 10 minutes and then a solution of 7.85 g (40 mmol) of 2,3,4-trimethoxybenzaldehyde in 40 ml of tetrahydrofuran was added within 10 minutes. The reaction mixture was brought to room temperature, stirred for 15 minutes and treated with 60 ml of saturated ammonium chloride solution. The aqueous phase was extracted twice with ether. The combined organic phases were washed in succession with saturated sodium chloride solution and with water, dried over sodium sulphate and concentrated. The residue was purified by flash chromatography on 500 g of silica gel (elution agent methylene chloride/ethyl acetate 9:1). There was obtained methyl 4-hydroxy-4-(2,3,4 -trimethoxyphenyl)-2-butynoate as a red oil.
Workup
- customwas brought to room temperature
- stirringstirred for 15 minutes
- extractionThe aqueous phase was extracted twice with ether
- washThe combined organic phases were washed in succession with saturated sodium chloride solution and with water
- dry with materialdried over sodium sulphate
- concentrationconcentrated
- customThe residue was purified by flash chromatography on 500 g of silica gel (elution agent methylene chloride/ethyl acetate 9:1)
Sources & evidence
- ORD record
- ord-1c3096bf2e5e4f8ab2e0f336e23d8b7f
- Source dataset
- uspto-grants-1990_05
- Patent number
- US04929741
Reaction notes
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