STEREOSELECTIVE SYNTHESIS OF<i>TRANS</i>-β-METHOXYCARBONYL-γ-ARYL-γ-BUTYROLACTONES
作者:Yali Chen、Weiyu Ding、Weiguo Cao、Cheng Lu
DOI:10.1081/scc-120004845
日期:2002.1
(5) by the reaction of methoxycarbonylmethyl triphenyl arsonium bromide (1) and 2,2-dimethyl-5-substituted-benzal-1,3-dioxa-4,6-dioxa-4,6-dione (2) is carried out in the presence of potassium carbonate and trace water in dimethoxyethane. 1,2-Cis-cyclopropane 3 is formed as an intermediate. The stability of compound 3 in water is related to the property of the aryl substituent. With strong electron-donating
摘要 通过甲氧基羰基甲基三苯基溴化砷鎓 (1) 和 2,2-二甲基-5-取代-苄基-1,3-二氧杂环己烷-反应立体选择性合成反式-β-甲氧基羰基-γ-芳基-γ-丁内酯 (5) 4,6-dioxa-4,6-dione (2) 在碳酸钾和痕量水的存在下在二甲氧基乙烷中进行。1,2-顺式环丙烷 3 作为中间体形成。化合物3在水中的稳定性与芳基取代基的性质有关。具有强给电子基团 [2a-c, Ar=4-CH3O-C6H4; 3,4-OCH2O-C6H3 或 4-(CH3)2N-C6H4] 在室温下 3 原位形成并立即转化为 γ-丁内酯 5a-c,而当芳基取代基为 H 或弱给电子或吸电子基团(2d-g,Ar=4-CH3-C6H4;C6H5;4-Cl-C6H4或4-NO2-C6H4),3在室温下对水稳定。在丙酮中进一步加热时,3 转化为 γ-丁内酯 5d-g(逐步合成)。还研究了 1 与 2d-g 反应一锅法合成