Hydrochloric Acid → (4S)-2,8-Dimethyl-4-[(toluenesulfonyl)amino]-5-nonanone

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Reaction Steps

To a stirred -78° C. solution of Ts-Leu (15 g, 53 mmol) in dry THF (240 ml) was added n-butyl lithium (57.8 ml of a 0.91M solution in hexane) followed 15 minutes later by isopentyl magnesium bromide (185 ml of a 0.8M solution in THF). The mixture was heated at reflux for 3 days, then cooled and poured into 0° C. 1M HCl (500 ml). The layers were separated and the aqueous phase was extracted with ether (3×150 ml). The combined organic layers were washed with saturated NaHCO3 (2×150 ml) and brine 150 ml). Drying and evaporating provided a residue which was chromatographed on silica gel to give 7.43 g (41%) of the desired product. Mass spectrum: (M+H)+ =340.

Provenance & Evidence