Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → 4-tert-butoxycarbonylamino-3-(tert-butoxycarbonylamino-methyl)-but-2-enoic Acid Ethyl Ester

Participants

Reaction Conditions

Reaction Steps

To a solution of (3-tert-butoxycarbonylamino-2-oxo-propyl)-carbamic acid tert-butyl ester (310 mg, 1.08 mmol) in benzene (20 mL) was added (carbethoxymethylene)-triphenyl phosphorane (825 mg, 2.37 mmol) and the reaction mixture was stirred at 45° C. overnight. Then the mixture was cooled to room temperature and the solvent concentrated down. Purification by radical chromatography on silica gel (2 mm plate, using CH2Cl2) afforded the desired compound as a yellow oil (290 mg, 75%). 1H NMR (CDCl3) δ 1.26 (t, 3H, J=9.0 Hz), 1.42 (s, 18H), 3.87 (d, 2H, J=6.0 Hz), 4.09 (d, 2H, J=6.0 Hz), 4.15 (q, 2H, J=9.0 Hz), 5.34 (br s, 1H), 5.85 (s, 1H), 7.34 (s, 1H).

Provenance & Evidence