Hexamethyldisilazane → Lithium Hexamethyldisilazide

Participants

Reaction Steps

To a THF (8 ml) solution of hexamethyldisilazane (615 μl), 1.66 ml of n-butyl lithium (1.56M, hexane solution) was added at -78° C., followed by stirring for 30 minutes to obtain a lithium hexamethyldisilazide solution. To this solution, a THF solution (10 ml) of 1.21 g of (1S,5R,6R,7R)-2-oxa-7-t-butyldimethylsiloxy-6-{(3S)-3-t-butyldimethylsiloxy-1-octynyl}-bicyclo[3.3.0]octan-3-one was dropwise added at -78° C., and the mixture was stirred for 30 minutes. Then, 930 mg of N-fluorobenzenesulfonimide was added thereto at -78° C. The mixture was stirred at -78° C. for 15 minutes, at 0° C. for 30 minutes and at room temperature for 30 minutes, and then poured into a saturated ammonium chloride aqueous solution. The mixture was extracted with ethyl acetate. The extract was purified by silica gel column chromatography (ethyl acetate:hexane=1:30 to 1:10) to obtain 643 mg of the above-identified compound.

Provenance & Evidence