3-Oxo-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester → 3-Methylene-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester

HRID 132099

Reaction equation

[CH2:1]([Li])CCC.[CH3:6][Si:7]([CH3:21])([CH3:20])[CH2:8][CH2:9][O:10][C:11]([CH:13]1[CH2:18][CH2:17][CH2:16][C:15](=O)[CH2:14]1)=[O:12]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.O1CCCC1>[C:11]([O-:12])(=[O:10])[CH3:13].[CH3:6][Si:7]([CH3:21])([CH3:20])[CH2:8][CH2:9][O:10][C:11]([CH:13]1[CH2:18][CH2:17][CH2:16][C:15](=[CH2:1])[CH2:14]1)=[O:12]

Participants

Conditions

Temperature: -10 °C

Procedure

A solution of 1.6 M n-butyllithium in hexanes (14.0 mL, 22.4 mmol) was added to a heterogeneous mixture of methyltriphenylphosphonium bromide (8.02 g, 22.4 mmol) in tetrahydrofuran (50 mL) at −10° C. After stirring for 30 min at −10° C., the yellow slurry was cooled to −78° C. and 3-oxo-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester (3.41 mg, 14.1 mmol) in tetrahydrofuran (20 mL) was added. After stirring for 10 min at −78° C., the dry ice/acetone bath was removed and the heterogeneous mixture was stirred for 3 h, during which time the solution warmed to ambient temperature. The heterogeneous mixture was concentrated and the residue was flash chromatographed with 99:1, 49:1, 24:1, and 23:2 hexanes:etheyl acetate as the eluant to yield 3.38 g (100% yield) of 3-methylene-cyclohexanecarboxylic acid 2-trimethylsilanyl-ethyl ester as a clear oil.

Workup

temperaturethe yellow slurry was cooled to −78° C.
stirringAfter stirring for 10 min at −78° C.
customthe dry ice/acetone bath was removed
stirringthe heterogeneous mixture was stirred for 3 h, during which time the solution
temperaturewarmed to ambient temperature
concentrationThe heterogeneous mixture was concentrated
customchromatographed with 99:1, 49:1, 24:1, and 23:2 hexanes

Sources & evidence

ORD record: ord-2574301570b546bbbd04d4f66b8d5256
Source dataset: uspto-grants-2008_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07385085B2

Linked notes

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