Pentane → methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]-4,4-dimethylpentanoate
Reaction equation
[O:1]1[C:6]2[CH:7]=[CH:8][C:9]([C:11]3[C:12]([C:18](=[CH2:23])[C:19]([O:21][CH3:22])=[O:20])=[C:13]([CH3:17])[S:14][C:15]=3[CH3:16])=[CH:10][C:5]=2[CH2:4][CH2:3][CH2:2]1.[C:24]([Li])([CH3:27])([CH3:26])[CH3:25].CCCCC>O1CCCC1>[O:1]1[C:6]2[CH:7]=[CH:8][C:9]([C:11]3[C:12]([CH:18]([CH2:23][C:24]([CH3:27])([CH3:26])[CH3:25])[C:19]([O:21][CH3:22])=[O:20])=[C:13]([CH3:17])[S:14][C:15]=3[CH3:16])=[CH:10][C:5]=2[CH2:4][CH2:3][CH2:2]1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -78 °C
Procedure
Under a nitrogen atmosphere, a solution of methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]prop-2-enoate (42c) (114 mg, 0.35 mmol) in anhydrous tetrahydrofuran (5 mL) was cooled to −78° C. tert-Butyllithium 1.6M in pentane (0.24 mL, 0.38 mmol) was added dropwise and the reaction mixture was stirred at −78° C. for 20 minutes before being quenched with brine (3 mL). The mixture was extracted with dichloromethane (2×6 mL). The organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by preparative TLC (cyclohexane/ethyl acetate 70/30) to provide the desired product (42d) (102 mg, 0.26 mmol, 76%) as a light yellow oil.
Workup
- additionwas added dropwise
- custombefore being quenched with brine (3 mL)
- extractionThe mixture was extracted with dichloromethane (2×6 mL)
- dry with materialThe organic layer was dried over sodium sulfate
- concentrationconcentrated in vacuo
- customThe residue was purified by preparative TLC (cyclohexane/ethyl acetate 70/30)
Sources & evidence
- ORD record
- ord-29878a34143b4866ad363c2cf895076e
- Source dataset
- uspto-grants-2016_01
- Patent number
- US09238026B2
Reaction notes
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