Elimination Reactions of Bicyclic Quaternary Salts. I. The Base Degradation of Tropinone Methiodide1
Elimination Reactions of Bicyclic Quaternary Salts. I. The Base Degradation of Tropinone Methiodide1
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DOI：
10.1021/ja01621a063
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发表时间：
1955-08
影响因子：
15
通讯作者：
J. Meinwald;S. Emerman;N. Yang;G. Büchi
中科院分区：
文献类型：
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作者：
J. Meinwald;S. Emerman;N. Yang;G. Büchi
托品酮碘甲烷（I）的碱性降解产物（迄今为止被认为是二氢苯甲醛（II））显示为环庚二烯酮的混合物。混合物的一个组分，环庚二烯-3，5-酮（VI），已被分离和表征。还得到了环庚二烯-2，4-酮（V）生成的证据。本文讨论了这些二烯酮以及托品酮和托品烯的Diels-Alder反应，并根据可靠的降解证据和独立的合成补充，确定了托品酮的结构。因此，根据反应式1，托品酮甲碘化物（I）在各种碱性条件下转化为二甲胺和二氢苯甲醛（II）的报道是相当令人惊讶的。[3]这样的转化需要将七元环收缩为环己烷衍生物。几种不同的碱催化羰基化合物的缩环是众所周知的，这为所报道的缩环反应提供了一些形式上的类比。
The base degradation product of tropinone methiodide (I), hitherto considered to be a dihydrobenzaldehyde (II), is shown to be a mixture of cycloheptadienones. One component of the mixture, cycIoheptadien-3, 5-one (VI), has been isolated and characterized. Evidence for the formation of cycloheptadien-2, 4-one (V) was also obtained. TheDiels-Alder reactions of these dienones as well as of tropone and tropilidene are discussed.The structure oftropinone is firmly established on the basis of sound degradative evidence supple-mented by independent syntheses. 2 The report that tropinone methiodide (I) is converted under a variety of basic conditions into dimethylamineand a dihydrobenzaldehyde (II) according to equation 1 is, therefore, rather surprising. 3 Such a transformation would necessitate the contraction of the seven-membered ring to a cyclohexane derivative. Several different base-catalyzed ring contractions of carbonyl compounds are well known, which provide some formal analogy for the reported