Sodium hydride → [(R)-1-(2-cyanocyclopropyl)-ethyl]-carbamic acid tert-butyl ester

Participants

Reaction Steps

DMSO was added to trimethylsulfonium iodide (1.79 g, 8.15 mmol) and sodium hydride (60% in mineral oil, 326 mg, 8.15 mmol) at 0° C. Then a 3:1 E:Z mixture of ((R)-3-cyano-1-methyl-allyl)-carbamic acid tert-butyl ester (0.4 g, 2.04 mmol) in DMSO was added. The reaction mixture was left to warm up to room temperature overnight. The reaction was stirred at room temperature for 2 days then diluted with water and ethyl acetate. The organic layers were dried over MgSO4 and concentrated in vacuo. The crude material was purified by flash chromatography (silica gel, 80 g, 20% to 50% EtOAc in hexanes) to provide [(R)-1-(2-cyanocyclopropyl)-ethyl]-carbamic acid tert-butyl ester as two discreet diastereomers (arbitrarily assigned). Diastereomer A (250 mg, 58%) as a colorless oil; MS: (M+H)+=211. Diastereomer B (130 mg, 30%) as a white powder; M+Na)+=233.

Provenance & Evidence