Ethyl Acetate → 6-Bromo-8-cyclopropyl-2,2,4,4-tetramethyl chroman

HRID 1936035Notes

Reaction equation

HRID 1936035 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[C:10]([CH:12]=[CH2:13])[CH:11]=1)[O:8][C:7]([CH3:15])([CH3:14])[CH2:6][C:5]2([CH3:17])[CH3:16].[N+](=[CH2:20])=[N-].C(OCC)(=O)C>C(OCC)C.CCCCCC.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[C:10]([CH:12]3[CH2:20][CH2:13]3)[CH:11]=1)[O:8][C:7]([CH3:15])([CH3:14])[CH2:6][C:5]2([CH3:17])[CH3:16]

Participants

7

Reactant 3

HCID 8857Ethyl AcetateHCID 9550DiazomethaneHCID 225689226-Bromo-8-vinyl-2,2,4,4-tetramethyl-chroman2×

Product 1

HCID 181779666-Bromo-8-cyclopropyl-2,2,4,4-tetramethyl chroman

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 3283Diethyl EtherSolvent2×HCID 8058HexaneSolvent

Procedure

A stirred, cooled (−30° C.) solution of 6-bromo-8-vinyl-2,2,4,4-tetramethyl chroman (Intermediate 31, 0.37 g, 1.26 mmol) in diethyl ether was treated with a solution of diazomethane in diethyl ether and catalytic amount of palladium (II)acetate (˜30 mg). The reaction mixture was allowed to warm to ambient temperature and subjected to flash column chromatography over silica gel (230-400 mesh) using 2% ethyl acetate in hexane as the eluent to afford the title compound as a clear, pale yellow oil (0.376 g, 97%).

Sources & evidence

ORD record
ord-53564fd27d4e4246b4d9ec191b4b8694
Source dataset
uspto-grants-2002_05
Patent number
US06387951B1

Reaction notes

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