Lithium Hexamethyldisilazide → N,N-Bis(trimethylsilyl)-(1R)-1-[(3aS,4S,6S,7aR)-hexahydro-3a,5,5-trimethyl-4,6-methano-1,3,2-benzodioxaborol-2-yl]-3-methylbutylamine

Participants

Reaction Conditions

Reaction Steps

A 1.0 M solution of lithium bis(trimethylsilyl)amide in tetrahydrofuran (189 ml, 0.189 mol) was added, over 30 minutes, to a solution of crude 2-[(1S)-1-chloro-3-methylbutyl]-(3aS,4S,6S,7aR)-hexahydro-3a,5,5-trimethyl-4,6-methano-1,3,2-benzodioxaborole of Step 2 (59.0 g, 91% purity, 0.189 mol) in tetrahydrofuran (580 ml) while cooling at −78° C. The reaction mixture was allowed to slowly warm to room temperature overnight. The solvent was removed by rotary evaporation and the residue taken up with dry hexane (800 ml). The resulting suspension was stirred at room temperature for 2 hours, then the solid was removed by filtration on a celite cake, which was washed with dry hexane (3×100 ml). The filtrate was concentrated giving a satisfactorily pure product as a brown oil (79 g) in practically quantitative yield. The product was used for the subsequent step without further purification.

Provenance & Evidence