Phthalimide → (4R)-4-(4,5-diphenyloxazol-2-yl)-4-phthalimido-1-butene

Participants

Reaction Steps

To a solution of (4S)-4-(4,5-diphenyloxazol-2-yl)-4-hydroxy-1-butene (9.2 g) in THF (100 ml) were added phthalimide (7.0 g) and triphenylphosphine (12.5 g) and diethyl azodiformate (7.5 ml) at room temperature. The mixture was stirred for 2 hours at room temperature and partitioned between ethyl acetate and water. The organic layer was washed with 1N-HCl, water, sat. NaHCO3 and brine. The dried solvent was evaporated in vacuo and the residue was purified by chromatography on silica gel to give (4R)-4-(4,5-diphenyloxazol-2-yl)-4-phthalimido-1-butene (9.7 g). MS (m/z): 421 (M+ +1) IR (Nujol): 1760, 1710 cm-1NMR (CDCl3, δ): 3.1-3.4 (2H, m), 5.0-5.3 (2H, m), 5.63 (1H, dd, J=6.0, 10.0 Hz), 5.7-6.0 (1H, m), 7.2-8.0 (14H, m) HPLC; chiralcel OD, 10% isopropanol/hexane, 32.2 ml/min

Provenance & Evidence