Ethyl Acetate → 6-Bromo-3 4-dihydro-4,4-dimethyl-8-vinylspiro[2H-1-benzopyran-2,1'-cyclopropane]

HRID 395070

Reaction equation

HRID 395070 reaction equation
[CH2:1]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Br:21][C:22]1[CH2:23][C:24](=[C:36]=O)[C:25]2[O:32][C:29]3([CH2:31][CH2:30]3)[CH2:28][C:27]([CH3:34])([CH3:33])[C:26]=2[CH:35]=1.C(OCC)(=O)C>CCCCCC>[Br:21][C:22]1[CH:23]=[C:24]([CH:36]=[CH2:1])[C:25]2[O:32][C:29]3([CH2:31][CH2:30]3)[CH2:28][C:27]([CH3:34])([CH3:33])[C:26]=2[CH:35]=1

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 137960MethylenetriphenylphosphoraneHCID 181779686-bromo-8-carbonyl-3,4-dihydro-4,4-dimethylspiro [2H-1-benzopyran-2,1'-cyclopropane]2×

Product 1

HCID 225688556-Bromo-3 4-dihydro-4,4-dimethyl-8-vinylspiro[2H-1-benzopyran-2,1'-cyclopropane]

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

Following general procedure N and using A solution of methylidene triphenyl phosphorane [generated from methyl triphenylphosphonium bromide (7 g, 20 mmol) and 1.6M solution of n-butyl lithium in hexanes (11.8 mL, 19 mmol) ], 6-bromo-8-carbonyl-3,4-dihydro-4,4-dimethylspiro[2H-1-benzopyran-2,1′-cyclopropane] (Intermediate 40, 2.06 g, 7 mmol) followed by flash column chromatography over silica gel (230-400 mesh) using 1-2% ethyl acetate in hexane as the eluent, the title compound was obtained as a clear oil (1.36 g, 66%).

Sources & evidence

ORD record
ord-ce516dc27de5469dba2c40e2966091a0
Source dataset
uspto-grants-2003_08
Patent number
US06603019B2

Linked notes

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