Bromotrichloromethane → 5-bromo-3,4,5,6-tetrahydro-4,4-dimethyl-6-trichloromethyl-2H-pyran-2-one
Reaction equation
[CH3:1][C:2]1([CH3:9])[CH:7]=[CH:6][O:5][C:4](=[O:8])[CH2:3]1.Br[C:11]([Cl:14])([Cl:13])[Cl:12].C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1.[Br:33]C1C(C(Cl)(Cl)Cl)OC(=O)C(C)(C)C1>>[Br:33][CH:7]1[CH:6]([C:11]([Cl:14])([Cl:13])[Cl:12])[O:5][C:4](=[O:8])[CH2:3][C:2]1([CH3:9])[CH3:1]Participants
5
Conditions
- Temperature
- 100 °C
Procedure
A mixture of 1.0 g (7.93 mmol) of 3,4-dihydro-4,4-dimethyl-2H-pyran-2-one and 6.29 g (31.7 mmol) of bromotrichloromethane was heated to 100° C. Heating was maintained at 100° C. for 12 hours. During this time 600 mg (2.48 mmol) of benzoyl peroxide was added in six 100 mg portions; a 100 mg portion being added approximately every 2 hours. The reaction mixture was cooled and placed on a silica gel packed chromatography column. Elution with 20:1 hexane:ethyl acetate mixture afforded 1.45 g, 56% yield, of 5-bromo-3,4,5,6-tetrahydro-3,3-dimethyl-6-trichloromethyl-2H-pyran-2-one.
Workup
- temperatureHeating
- temperaturewas maintained at 100° C. for 12 hours
- additiona 100 mg portion being added approximately every 2 hours
- temperatureThe reaction mixture was cooled
- washElution with 20:1 hexane
- customethyl acetate mixture afforded 1.45 g, 56% yield
Sources & evidence
- ORD record
- ord-52392cc812e6461794e45a74860751e3
- Source dataset
- uspto-grants-1987_10
- Patent number
- US04701539
Reaction notes
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