Lithium Hexamethyldisilazide → 2-(1-Methylethyl)-5,9,13-trimethyl-1-trimethylsiloxy-2,4,8,12-cyclotetradecatetraene-1-carbonitrile

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Reaction Steps

A solution of lithium bis(trimethylsilyl) amide (5.0 mmol, 0.25 M) in dry tetrahydrofuran (20 ml) is stirred under argon atmosphere on an oil bath at 40° C. and thereto is dropwise added a solution of the cyanohydrin trimethylsilyl ether which is 15-chloro-3-(1-methylethyl)-6,10,14-tri-methyl-2-trimethylsiloxy-3,5,9,13-pentadecatetraenenitrile (378 mg, 0.895 mmol) prepared in Reference Example 5 in dry tetrahydrofuran (15 ml) over 50 minutes. After stirring the mixture at this temperature for 20 minutes, the reaction is quenched by adding a saturated aqueous ammonium chloride solution while stirring on an ice-water bath. After removing tetrahydrofuran by distillation under reduced pressure, the organic layer is extracted with ether. The obtained extract is purified by silica gel column chromatography (n-hexane/ethyl acetate =60:1) to give 2-(1-methylethyl)-5,9,13-trimethyl-1-trimethylsiloxy -2,4,8,12-cyclotetradecatetraene-1-carbonitrile (288 mg, 83%) and 2-(1-methylethyl)-5,9,13-trimethyl-2,4,8,12-cyclotetradecatetraene-1-on (42.9 mg, 16%).

Provenance & Evidence