trans-Crotonyl chloride → (4S)-3-[(2E)-But-2-enoyl]-4-phenyl-1,3-oxazolidin-2-one

Participants

Reaction Steps

To a stirred solution of (4S)-4-phenyl-1,3-oxazolidin-2-one (12 g, 73.5 mmol) in THF (200 mL) was added n-BuLi (2.5 M, 29.4 mL, 73.5 mmol) dropwise via a syringe at −78° C. The resulting reaction mixture was stirred at −78° C. for 5 minutes before (2E)-but-2-enoyl chloride (8.46 mL, 88.0 mmol) was added dropwise via a syringe. The reaction mixture was allowed to warm to ambient temperature and was quenched by addition of brine (100 mL) and water (100 mL). A mixture of ethyl acetate and hexanes (1:2, 100 mL) was added to partition the mixture and the organics were separated, dried over sodium sulfate, filtered and concentrated. The resultant oil was recrystallized in 5% ethyl acetate in hexanes (after seeding with crystals obtained from earlier batches) to yield (4S)-3-[(2E)-but-2-enoyl]-4-phenyl-1,3-oxazolidin-2-one (15.7 g, 67.9 mmol). 1H NMR (500 MHz, CDCl3) δ7.4 (m, 6H), 5.5 (m, 1H) 4.73 (t, J=8.8 Hz, 1H), 4.30 (m, 1H), 1.97 (dd, J=6.8, 1.5 Hz, 3H).

Provenance & Evidence