syn-[2.2]Paracyclonaphthane
syn-[2.2]Paracyclonaphthane
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顺式-[2.2]对环萘烷
DOI：
10.1021/ja01037a033
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发表时间：
1969
影响因子：
15
通讯作者：
P. Keehn
中科院分区：
文献类型：
--
作者：
H. Wasserman;P. Keehn
图2. 1，4-二甲基萘（A）、（B）和（？）[2.2]对环萘（la）和（C）j>？- [2.2]对环萘（lb）。最近描述的III的生成，仅形成反结构Ia。我们现在希望报道通过对早期方法1· 3的改进来分离顺式[2.2]对环萘（lb），该方法采用稍高的温度来分解季氢氧化物lib。用银氧化物（46 g，0.2 mol）以通常的方式1处理季溴化物IIa（58.8 g，0.2 mol）24小时，然后过滤并在3 l中共沸除去水。在吩噻嗪（1g）的存在下，用二甲苯4处理12小时，得到溶液，将其过滤以除去聚合物。将滤液蒸发至干，并将残余物在硅胶上层析。用己烷连续洗脱，首先得到12.6g（41%）反式异构体1a，接着得到含有顺式和反式异构体混合物的级分。将这些馏分从苯中分级结晶，并在己烷中在制备薄层板上进行色谱分析，得到1.3g（4.1%）纯lb。顺式异构体从苯中结晶为白色棱柱，熔点243-245。Anal.对于C24 H2O计算：C，93.46; H，6.54。实测值：C，93.35; C，6.71。通过下文概述的光谱数据建立了顺式结构，并通过独立的X射线晶体学分析证实。5
Figure 2. Nmr spectra (60 Me) of (A) 1, 4-dimethylnaphthalene,(B) an?/-[2.2] paracyclonaphthane (la), and (C) j>?¡-[2.2] paracyclonaphthane (lb). recently described for the generation of III, only the anti structure la was formed. We now wish to report the isolation of the syn form of [2.2] paracyclonaphthane (lb) by a modification of earlier procedures1· 3 which employs a somewhat higher temperature for the de-composition of the quaternary hydroxide lib. Treatment of the quaternary bromideIla (58.8 g, 0.2 mol) with silver oxide (46 g, 0.2 mol) for 24 hr in the usual manner1 followed by filtration and azeo-tropic removal of water in 3 1. of xylene4 for 12 hr in the presence of phenothiazine (1 g) afforded a solution which was filtered to remove polymer. The filtrate was evaporated to dryness and the residue chromato-graphed on silica gel. Continuous elution with hexane afforded, first, 12.6 g (41%) of the anti isomer la, fol-lowed by fractions containing a mixture of syn and anti isomers. Fractional crystallization of these fractions from benzene and chromatography on preparative thin layer plates in hexane gave 1.3 g (4.1%) of pure lb. The syn isomer crystallizes from benzene as white prisms, mp 243-245. Anal. Caled for C24H20: C, 93.46; H, 6.54. Found: C, 93.35;, 6.71. The syn structure was established by the spectroscopic data outlined below and confirmed by an independent X-ray crystallographic analysis. 5