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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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.

Herkunft & Nachweise