Metacyclophanes and related compounds. 1. Preparation and nuclear magnetic resonance spectra of 8,16-disubstituted [2.2]metacyclophanes
Metacyclophanes and related compounds. 1. Preparation and nuclear magnetic resonance spectra of 8,16-disubstituted [2.2]metacyclophanes
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间环芬及相关化合物。
DOI：
10.1021/jo00335a047
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发表时间：
1981
影响因子：
3.6
通讯作者：
T. Yamato
中科院分区：
文献类型：
--
作者：
M. Tashiro;T. Yamato
本文报道了8，16-双（烷氧基甲基）-（3a-j），8，16-双（碘甲基）-（4a，B），8，16-双（乙酰基羟甲基）-（5a，B），8，16-二羟基-（6a，B）和8，16-双（吡啶甲基）[2.2]间环芳的合成。制备了相应的2-取代5-叔丁基对二甲苯（BMX），作为MCP的测定和~（13）CNMR谱的参考物质。根据[2.2]间环芳烷（MCP）与BMX相应质子的化学位移之差（），判断了对侧芳环的环电流对MCP内部质子的影响。环电流对化学位移的影响似乎与质子离同侧芳环的距离有关，而与MCP中8位和16位基团的种类无关。最近，Boekelheide和他的同事报道了8-单取代和8，16-二取代[2.2]间环芳（MCP）的合成，并发现它们的内部烷基质子由于相对芳环的环电流而发生高场位移。7.虽然在具有烷基以外的内部取代基的MCP的7 H NMR谱中可能观察到这种高场位移，但迄今为止还没有关于上述问题的任何报道。虽然Sato和他的同事们已经研究了一些[2.2]间环芳烷的13 C NMR谱，但是8，16-二取代的[2.2]间环芳烷的13 C NMR谱还没有报道11 '14。我们以前报道了8，16-二甲基-（1a）和5，13-二叔丁基-8，16-二甲基[2.2]-
Preparation of 8, 16-bis (alkoxymethyl)-(3a—j), 8, 16-bis (iodomethyl)-(4a, b), 8, 16-bis (acetylhydroxymethyl)-(5a, b), 8, 16-dihydroxy-(6a, b), and 8, 16-bis (pyridiniummethyl)[2.2] metacyclophanes was described. The cor-responding 2-substituted 5-tert-butyl-ro-xylenes (BMX) were also prepared as reference materials for the de-termination of and 13C NMR spectra of MCP. On the basis of the differences () of the chemical shifts of the internal protons of the [2.2] metacyclophanes (MCP) from the corresponding protons of BMX, the effect of ring current of the opposite aromatic ring on the internal protons of MCP was judged. The ring current effect on the chemical shifts seems be associated with the distance of the protons from the same side aromatic ring rather than the kind of the groups in positions 8 and 16 in MCP. There was no effect of the ring current on the internal carbons of MCP inthe measurement of 13C NMR.Recently, Boekelheide and hisco-workers1'10 have re-ported the synthesis of interesting 8-mono-and 8, 16-di-substituted [2.2] metacyclophanes (MCP) and found that their internal alkyl protons show upfield shifts due to the ring current of the opposite aromatic ring. 7 Although such upfield shifts might be observed in 7H NMR spectra of MCP having internal substituents other than alkyl groups there has not been any report concerning the above problem so far. Although Sato and his co-workershave studied 13C NMR spectra of some [2.2] metacyclophanes, the 13C NMR spectra of 8, 16-disubstituted [2.2] meta-cyclophanes11'14 have not been reported. We previously reported that15 the bromination of 8, 16-dimethyl-(la) and 5, 13-di-fert-butyl-8, 16-dimethyl [2.2]-