Dimethyl methylphosphonate → (S)-tert-Butyl 1-(dimethoxyphosphoryl)-2-oxohex-5-en-3-ylcarbamate

Participants

Reaction Steps

To a solution of dimethyl methylphosphonate (15.85 mL, 148 mmol) in THF (99 mL) at −78° C. was added n-butyllithium (93 mL, 148 mmol) slowly. After addition was completed, the reaction mixture was stirred for 30 min and then a solution of (S)-methyl 2-(tert-butoxycarbonylamino)pent-4-enoate (6.8 g, 29.7 mmol) in THF (15 mL) was added slowly. Stirring was continued for another 40 min at −78° C. The reaction was then quenched by adding water and diluted with EtOAc. The organic layer was washed with 1 M HCl, saturated NaHCO3 and brine. The organic layer was then dried over MgSO4, filtered and concentrated to give a clear oil. The crude product was then purified by silica gel chromatography to give the desired product (9.3 g, 98%) as colorless oil. MS (ESI) m/z: 599.0 (M+Na)+.

Provenance & Evidence