[Cl-].[Li+].[CH2:3]([Mg]Br)[CH:4]=[CH2:5].Cl[Si](C)(C)C.[C:13]1(=[CH:16][C:17]([O:19][CH3:20])=[O:18])[CH2:15][CH2:14]1.N.[Cl-].[NH4+]>C1COCC1.C(OCC)C.C1CCCCC1.C(OCC)(=O)C>[CH3:20][O:19][C:17](=[O:18])[CH2:16][C:13]1([CH2:5][CH:4]=[CH2:3])[CH2:15][CH2:14]1
45.69 g (222.2 mmol) of copper(I) bromide/dimethyl sulfide complex and 9.42 g (222.2 mmol) of anhydrous lithium chloride were dissolved in 300 ml of THF, the mixture was cooled to −78° C. and 100 ml (200 mmol) of a 2 M solution of allylmagnesium bromide in diethyl ether were added slowly. 28.2 ml (222.2 mmol) of chlorotrimethylsilane and 11.21 g (100 mmol) of methyl cyclopropylideneacetate [CAS Registry No. 110793-87-8] were then added dropwise in succession to the reaction solution, and the mixture was stirred for about 5 min (monitored by TLC, mobile phase cyclohexane/ethyl acetate 20:1). 50 ml of an aqueous solution of ammonia/ammonium chloride (1:9) were then added, and the reaction solution was filtered through kieselguhr. The organic phase was separated off and the aqueous phase was extracted two more times with diethyl ether. The combined organic phases were then washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated under reduced pressure. The residue was dissolved in 100 ml of THF, and 222 ml (222 mmol) of a 1 M solution of tetrabutylammonium fluoride in THF were added. The reaction solution was stirred for another 10 min and then concentrated to dryness. The crude product obtained was purified chromatographically on silica gel (mobile phase cyclohexane/ethyl acetate 20:1). This gave 6.92 g (45 mmol, 45% of theory) of the title compound.
読み込み中…
