同分异构体的分离纯化？1.两者极性差别很大，过柱就可以分离 2.类似结构开环的参考文献 a. Journal of the American Chemical Society, 134(20), 8432-8435; 2012 (-)-Zonarol (14). (-)-isozonarol (15) and (+)-Chromazonarol 11 (15 mg, 0.048 mmol, 1.0 equiv) was dissolved in 500 μL CH2Cl2 and cooled to -78 °C. In a separate flask, 1.0 M BCl3 in hexanes (286 μL, 0.286 mmol, 6.0 equiv) was added to 2,6-di-tert-butyl-4-methylpyridine (118 mg, 0.572 mmol, 12.0 equiv) in 500 μL CH2Cl2 at room temperature, transferred to the solution of (+)-chromazonarol dropwise via cannula and stirred for 1 h at -78 °C. Solid NaHCO3 was added to the reaction mixture followed by EtOAc. The contents of the reaction flask were then added to a separatory funnel containing saturated NH4Cl and the layers were separated. The aqueous layer was extracted again with EtOAc, organic layers combined, washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The crude product was then purified on silica gel eluting with 20% EtOAc/hexanes. 2.9 : 1.0 : 0.3 mixture of (-)-isozonarol 15 : (-)-zonarol 14 : tetrasubstituted olefin 16 (12 mg, 80% combined yield) as an off-white solid. b. Bulletin of the Korean Chemical Society, 29(2), 515-518; 2008 c.Journal of the Chemical Society C: Organic, (4), 788-95; 1971 都是醋酸回流Treatment of compound 1 in refluxing AcOH for 2 h afforded compound 16 with oxabicyclononane moiety in 85% yield (Scheme 3).查看更多
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