Sodium bis(trimethylsilyl)amide → HCID 19965976, compound

Participants

Reaction Steps

8.6 ml (8.6 mmol) of a 1.0M tetrahydrofuran solution of sodium hexamethyldisilazide were added dropwise over a period of 20 minutes to a suspension of 5.04 g (8.67 mmol) of (4-t-butyl-3-nitrophenyl)methyltriphenylphosphonium iodide (prepared as described in Preparation 52) in 80 ml of tetrahydrofuran at -78° C., and the mixture was allowed to stand for 1 hour. A solution of 2.33 g (8.61 mmol) of (S)-2-t-butyldimethylsilyloxy-3-cyclohexylpropanol [prepared as described in step (iv) above] in 7 ml of tetrahydrofuran was then added all at once, and the resulting mixture was stirred for 1 hour at the same temperature. The cooling bath was then removed, and the mixture was stirred for a further 4 hours. The reaction was then stopped by adding a saturated aqueous solution of ammonium chloride, after which the reaction mixture was extracted with a 1:3 by volume mixture of ethyl acetate and hexane. The extract was washed with water and with a saturated aqueous solution of sodium chloride, in that order, after which it was dried over anhydrous magnesium sulfate. The solvent was then removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through 150 g of silica gel, using a 1:19 by volume mixture of diethyl ether and hexane as the eluent, to give fractions containing small amounts of impurities. These fractions were again purified by column chromatography through 150 g of silica gel, using a 1:4 by volume mixture of methylene chloride and hexane as the eluent, to give 2.78 9 (yield 72%) of the title olefin derivative as a colorless oil.

Provenance & Evidence