Boron trifluoride etherate → HCID 68544684, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of 22.35 g (117 mmol) CuI in 400 ml THF at −40° C. are added dropwise 70 ml (140 mmol) of a 2M THF solution of allylmagnesium chloride. After 1 h the mixture is cooled to −78° C. and 17.7 ml (140 mmol) BF3.OEt2 are added in 15 minutes. Then a solution of 41 g (117 mmol) (R)-3-((E)-but-2-enoyl)-4-isopropyl-5,5-diphenyl-oxazolidin-2-one in 100 ml THF is added as quickly as possible. The temperature rises to −40° C. Stirring is continued for 1 h and then the mixture is quenched with 500 ml 10% aqueous NH4Cl. The mixture is stirred for 1 h at 25° C. and filtered over celite and washed with 150 ml TBME. The organic phase is washed successively with water, 10% aqueous NaHCO3, water, 5% citric acid and water. Chromatography (silica gel, EE/hexane 1:10) of the crude product yields the (R)-4isopropyl-3-((R)-3-methyl-hex-5-enoyl)-5,5-diphenyl-oxazolidin-2-one.

Provenance & Evidence