Ethyl chloroformate → 4-Methyl-4-(tetrahydro-pyran-2-yloxy)-pent-2-ynoic acid ethyl ester
Reaction equation
[CH3:1][C:2]([CH3:12])([O:5][CH:6]1[CH2:11][CH2:10][CH2:9][CH2:8][O:7]1)[C:3]#[CH:4].C([Li])CCC.Cl[C:19]([O:21][CH2:22][CH3:23])=[O:20]>C1COCC1>[CH2:22]([O:21][C:19](=[O:20])[C:4]#[C:3][C:2]([CH3:12])([O:5][CH:6]1[CH2:11][CH2:10][CH2:9][CH2:8][O:7]1)[CH3:1])[CH3:23]Participants
5
Conditions
- Temperature
- -78 °C
Procedure
To a solution of 2-(1,1-dimethyl-prop-2-ynyloxy)-tetrahydropyran (10.0 g, 59.4 mmol) in THF (100 mL), cooled to −78° C. was added n-butyl lithium (26 mL, 65 mmol) as a solution in hexanes. The mixture was stirred at −78° C. for 1 h then a solution of ethyl chloroformate (7.0 mL, 108.5 mmol) in THF (100 mL) was added dropwise. The mixture was stirred at −78° C. for 1 h then quenched by addition of a saturated aqueous solution of ammonium chloride. This mixture was diluted with water and extracted with ethyl acetate. The organic phase was dried (sodium sulfate) and concentrated to provide 7.5 g (53%) of 4-methyl-4-(tetrahydro-pyran-2-yloxy)-pent-2-ynoic acid ethyl ester as a clear oil.
Workup
- stirringThe mixture was stirred at −78° C. for 1 h
- customthen quenched by addition of a saturated aqueous solution of ammonium chloride
- additionThis mixture was diluted with water
- extractionextracted with ethyl acetate
- dry with materialThe organic phase was dried (sodium sulfate)
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-ce160fa6f3034de1b14f5d71f90c6257
- Source dataset
- uspto-grants-2009_09
- Patent number
- US07592353B2
Reaction notes
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