Radical Addition of 2-Iodoalkanamide or 2-Iodoalkanoic Acid to Alkenes with a Water-Soluble Radical Initiator in Aqueous Media: Facile Synthesis of<i>γ</i>-Lactones
作者:Hideki Yorimitsu、Katsuyu Wakabayashi、Hiroshi Shinokubo、Koichiro Oshima
DOI:10.1246/bcsj.74.1963
日期:2001.10
Radical reactions in water or aqueous ethanol using a water-soluble radical initiator are described. Heating a mixture of 2-iodoacetamide and 5-hexen-1-ol in water at 75 °C in the presence of a water-soluble radical initiator, 4,4′-azobis(4-cyanopentanoic acid), afforded 5-(4-hydroxybutyl)dihydrofuran-2(3H)-one in 95% yield. The use of 2-iodoacetic acid in place of 2-iodoacetamide also gave the same γ-lactone in 93% yield. The reaction of 2-iodoacetamide with 1-octene in aqueous ethanol was initiated by 2,2′-azobis(2-methylpropanamidine) dihydrochloride to provide γ-decanolactone. Employing water as a solvent is crucial to obtain lactone in satisfactory yield.
在水或含水乙醇中使用水溶性自由基引发剂的剧烈反应已有报道。将2-碘代乙酰胺和5-己烯-1-醇的混合物在75°C下加热,并加入水溶性自由基引发剂4,4′-偶氮双(4-氰基戊酸),可得到产率为95%的5-(4-羟基丁基)二氢呋喃-2(3H)-酮。使用2-碘代乙酸代替2-碘代乙酰胺也能以93%的产率得到相同的γ-内酯。在含水乙醇中,通过2,2′-偶氮双(2-甲基丙酰胺)二盐酸盐引发2-碘代乙酰胺与1-辛烯的反应,得到γ-癸醇内酯。使用水作为溶剂对于获得高产率的乳酮至关重要。