Tetrahydrofuran → tert-butyl (2R, 3S, 5S)-6-oxo-2,3-diphenyl-5-(3-(trimethylsilyl)benzyl)-4-morpholinecarboxylate

Participants

Reaction Conditions

Reaction Steps

A dry 250 mL 3-necked flask equipped with a magnetic stirrer and a nitrogen inlet was charged with 2.08 g of t-butyl (2R, 3S)-(-)-6-oxo-2,3-diphenyl-4-morpholinecarboxylate (Aldrich), 1.43 g of 3-(trimethylsilyl)benzyl bromide (Yamakawa, T., et al, J. Med. Chem., 1990, 33, 1430), and 45 mL of anhydrous THF. The solution was cooled to -78° C. and was treated with 6.17 mL of 1 M sodium bis(trimethylsilyl)amide/THF (Aldrich) via syringe through a rubber septum. The solution was stirred at -78° C. for 3.5 h and was then poured into 150 mL of water. The resulting mixture was extracted with EtOAc (4×50 mL). The combined EtOAc extracts were washed with saturated brine (3×100 mL), dried over anhydrous Na2SO4, and concentrated in vacuo to give a light yellow oil. The crude material was purified by flash chromatography on silica gel (9:1 hexane:EtOAc) to afford 2.6 g (88%) of tert-butyl (2R, 3S, 5S)-6-oxo-2,3-diphenyl-5-(3-(trimethylsilyl)benzyl)-4-morpholinecarboxylate as a white powder, m.p. 88-90° C.

Provenance & Evidence