The preparation of 3-substituted-1,5-dibromopentanes as precursors to heteracyclohexanes
作者:Bryan Ringstrand、Martin Oltmanns、Jeffrey A Batt、Aleksandra Jankowiak、Richard P Denicola、Piotr Kaszynski
DOI:10.3762/bjoc.7.49
日期:——
The methodology to prepare 3-substituted 1,5-dibromopentanes I and their immediate precursors, which include 3-substituted 1,5-pentanediols VII or 4-substituted tetrahydropyrans VIII, is surveyed. Such dibromides I are important intermediates in the preparation of liquid crystalline derivatives containing 6-membered heterocyclic rings. Four dibromides 1a-1d containing simple alkyl and more complex
研究了制备 3-取代的 1,5-二溴戊烷 I 及其直接前体(包括 3-取代的 1,5-戊二醇 VII 或 4-取代的四氢吡喃 VIII)的方法。这种二溴化物I是制备含有6元杂环的液晶衍生物的重要中间体。制备了四种二溴化物 1a-1d,在 3 位含有简单的烷基和更复杂的片段。3-丙基-和3-戊基-戊烷-1,5-二醇(2a,b)从戊二酸或丙二酸二酯开始制备,而四氢吡喃3c和3d从四氢-4H-吡喃-4-酮获得。讨论了每条路线的优缺点。二溴化物 1c 和 1d 用于制备锍两性离子 11c 和 11d。