tert-butyl N-[(3S)-1-diazo-5-methyl-2-oxohexan-3-yl]carbamate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Boc-LeuCHN2 (4.40 g, 17.2 mmoles) was dissolved in 50 mL of ether and cooled to 0°; anhydrous 3.45N ethanolic:HCl (5.22 mL, 18.0 mmoles) was added. After about 5 minutes, the resulting solution was washed with cold water, saturated aqueous sodium chloride, and was dried over anhydrous sodium sulfate. Solvent was evaporated to yield crystalline Boc-LeuCH2Cl. Product was isolated and washed with petroleum ether to yield 0.84 g (mp 65°-66°) in a first crop and 1.94 g (mp 64°-65.5°) in a second crop isolated from cold petroleum ether. cooled to 0° the resulting solution was washed with cold water, saturated aqueous sodium chloride was dried over anhydrous sodium sulfate Solvent was evaporated