Synthesis of 7-Azabicyclo[2.2.1]heptane and 2-Oxa-4-azabicyclo[3.3.1]non-3-ene Derivatives by Base-Promoted Heterocyclization of Alkyl <i>N</i>-(<i>cis</i>(<i>trans</i>)-3,<i>trans</i>(<i>cis</i>)-4-Dibromocyclohex-1-yl)carbamates and <i>N</i>-(<i>cis</i>(<i>trans</i>)-3,<i>trans</i>(<i>cis</i>)-4-Dibromocyclohex-1-yl)-2,2,2-trifluoroacetamides
作者:Elena Gómez-Sánchez、Elena Soriano、José Marco-Contelles
DOI:10.1021/jo701625a
日期:2007.11.1
trans-4-dibromocyclohex-1-yl)carbamate (10) with sodium hydride in DMF at room temperature provides 2-bromo-7-[(tert-butoxy)carbonyl]-7-azabicyclo[2.2.1]heptane (2) (52% yield), whose t-BuOK-promoted hydrogen bromide elimination affords 7-[(tert-butoxy)carbonyl]-7-azabicyclo[2.2.1]hept-2-ene (31) in 78% yield, an intermediate in the total synthesis of epibatidine (1). However, the NaH/DMF-mediated heterocyclization
我们已经研究了烷基N-(顺式(反式)-3,反式(顺式)-4-二溴环己基-1-基)氨基甲酸酯和N-(顺式(反式)-3,反式(顺式)- 4-二溴环己基-1-基)-2,2,2-三氟乙酰胺,研究了氮保护基的作用以及C3和C4处离去基团的相对构型对反应结果的影响。我们已经观察到氢化钠促进烷基N-(顺-3,反-4-二溴环己基-1-基)氨基甲酸酯的杂环化(10,12,14,16,18)为7-氮杂双环[2.2.1]庚烷衍生物的合成的便利方法。例如,在室温下,叔丁基N-(顺式-3,反式-4-二溴环己基-1-基)氨基甲酸酯(10)与氢化钠在DMF中的反应可提供2-溴-7-[(叔丁氧基)羰基] -7-氮杂双环[2.2.1]庚烷(2)(52%收率),通过t -BuOK促进的溴化氢消除可得到7-[((叔丁氧基)羰基] -7-氮杂双环[2.2.1]。 ]庚-2-烯(31)以78%的产率收率,是Epibatidine(