反应详情

温度

-78 °C

A solution of 9.63 g (29.81 mmol) of 2-(4,5-dibromo-2-furanyl)-4,4-dimethyloxazoline in dry tetrahydrofuran (30 mL) is added dropwise to a -78° C. solution of freshly generated lithium diisopropylamide (33.89 mmol, 1.14 equiv) in tetrahydrofuran (80 mL) under an argon atmosphere. The resulting solution is stirred at -78° C. for 10 min and a solution of 5.49 g (46.49 mmol, 1.56 equiv) of isopropyl sulfide in tetrahydrofuran (20 mL) is added dropwise to the reaction. The reaction is stirred for 3.75 hr at -78° to -10° C. and poured onto 5% aqueous HCl (350 mL). The resulting aqueous solution is extracted with diethyl ether (4X). The combined organic extracts are washed with aqueous saturated NaCl, dried (Na2SO4), and concentrated in vacuo. Flash chromatography (SiO2, 7×25 cm, 10% CH2Cl2 /10% ethyl acetate/hexane) affords 7.67 g (11.84 g theo.; 65%) of the desired product as a yellow solid. Recrystallization from hexane affords an analytical sample; mp 71°-72° C.

1. stirringThe reaction is stirred for 3.75 hr at -78° to -10° C.
2. extractionThe resulting aqueous solution is extracted with diethyl ether (4X)
3. washThe combined organic extracts are washed with aqueous saturated NaCl
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated in vacuo