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化学学报
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化学学报 ›› 2006, Vol. 64 ›› Issue (16): 1757-1760. 上一篇    

研究简报

10,10-二苄基-9(10H)蒽醇的酸催化选择性环化反应

高春梅1,2, 曹德榕*,1,3, 徐社阳1   

  1. (1中国科学院广州化学研究所纤维素化学重点实验室 广州 510650)
    (2中国科学院研究生院 北京 100039)
    (3华南理工大学化学科学学院 广州 510640)
  • 投稿日期:2005-12-02 修回日期:2006-03-13 发布日期:2006-08-28
  • 通讯作者: 曹德榕

Acid-catalyzed Selective Cyclization of 10,10-Dibenzyl-9(10H)-anthranol

GAO Chun-Mei1,2; CAO De-Rong*,1,3; XU She-Yang1   

  1. (1 Key Laboratory of Cellulose and Lignocellulosics Chemistry, Guangzhou Institute of Chemis-try, Chinese Academy of Sciences, Guangzhou 510650)
    (2 Graduate School of the Chinese Academy of Sciences, Beijing 100039)
    (3 College of Chemistry, South China University of Technology, Guangzhou 510640)
  • Received:2005-12-02 Revised:2006-03-13 Published:2006-08-28
  • Contact: CAO De-Rong

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蒽酮(1)与3,5-二甲氧基苯甲醛(2)在吡啶/哌啶中反应生成10-(3,5-二甲氧基苯甲亚基蒽酮(3); 3经Pd/C催化氢化生成10-(3,5-二甲氧基苄基蒽酮(4); 4与3-甲氧基苄基氯(5)进行相转移催化烷基化反应生成10-(3,5-二甲氧基苄基)-10-(3-甲氧基苄基)蒽酮(6); 6经NaBH4还原生成10-(3,5-二甲氧基苄基)-10-(3-甲氧基苄基)-9(10H)-蒽醇(7); 7在酸催化下发生选择性1,7-脱水反应, 生成高三蝶烯(homotriptycene) (8). 其反应机理可能是7在酸存在下生成正碳离子中间体, 然后选择性地亲电进攻富电荷的3,5-二甲氧基苯基, 而不进攻3-甲氧基苯基.

关键词: 蒽醇, 缩合, 三蝶烯, 亲电取代

Anthrone (1) reacted in pyridine/piperidine with 3,5-dimethoxybenzaldehyde (2) to give 10-(3,5-dimethoxybenzylidene)-9-anthrone (3). Catalytic hydrogenation (5% Pd on carbon) of 3 afforded 10-(3,5-dimethoxybenzyl)-9-anthrone (4). 10-(3,5-Dimethoxybenzyl)-10-(3-methoxybenzyl)-9-anthrone (6) was obtained by alkylation of anthrone 4 with 3-methoxybenzyl chloride (5). Subsequent reduction of 6 with NaBH4 gave 10-(3,5-dimethoxybenzyl)-10-(3-methoxybenzyl)-9(10H)-9-anthranol 7. 7 exhibits in the presence of formic acid or p-methylphenyl-sulfonic acid a selective 1,7-elimination of water which leads to homotriptycene (8). It could be assumed that the protonation of the hydroxy group leads to a carbenium ion intermediate which selectively attacks as electrophile the electron-rich benzene ring with 3,5-dimethoxy groups, instead of attacking the benzene ring with 3-methoxy group.

Key words: anthranol, condensation, triptycene, electrophilic substitution