Acetic Acid → HCID 71009034, compound

Participants

Reaction Conditions

Reaction Steps

A solution of (1S,2S)-rel-2-[(R)-2-ethoxycarbonyl-2,2-difluoro-1-methyl-1-((R)-2-methyl-propane-2-sulfinylamino)-ethyl]-cyclopropanecarboxylic acid tert-butylester (2.23 g, 5.42 mmol) in tetrahydrofuran (20 ml) was treated dropwise under nitrogen at 0° C. with a solution of lithium borohydride (2M in tetrahydrofuran; 5.42 ml, 10.8 mmol), at such a rate that the temperature was kept below 6° C. The orange reaction mixture was stirred at 0° C. for 3 hours. For the workup, acetic acid (654 mg, 623 μl, 10.8 mmol) was added dropwise, keeping the temperature below 10° C., followed by water (0.8 ml). After 70 minutes of stirring, brine and ethyl acetate were added and the mixture was extracted twice with ethyl acetate. The organic layer was washed with brine, dried over sodium sulphate and evaporated. A light green oil was obtained (2.31 g) which was purified by chromatography on silica gel using a gradient of heptane/ethyl acetate=100:0 to 0:100 as the eluent. The (1S,2S)-rel-2-[(R)-2,2-difluoro-3-hydroxy-1-methyl-1-((R)-2-methyl-propane-2-sulfinylamino)-propyl]-cyclopropanecarboxylic acid tert-butyl ester (1.19 g, 59% yield) was obtained as a colorless oil. MS (ISP): m/z=370.1 [M+H]+.

Provenance & Evidence