Synthesis of all stereoisomers of sulfinylcalix[4]arenes.
Synthesis of all stereoisomers of sulfinylcalix[4]arenes.
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DOI：
10.1021/jo026801x
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发表时间：
2003-02
期刊：
影响因子：
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通讯作者：
Naoya Morohashi;H. Katagiri;Nobuhiko Iki;Yu Yamane;C. Kabuto;T. Hattori;S. Miyano
中科院分区：
文献类型：
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作者：
Naoya Morohashi;H. Katagiri;Nobuhiko Iki;Yu Yamane;C. Kabuto;T. Hattori;S. Miyano
对叔丁基硫杯[4]芳烃[4]芳烃[4(Rcct)，4(Rcct)，4(Rctt)和4(Rtct)]的所有四个立体异构体都是通过氧化对叔丁基硫杯[4]芳烃(2)或其四邻苯基醚5得到的。因此，2与4.4摩尔当量的NaBO(3).4H(2)O反应分别得到rtct和rctt异构体，产率分别为27%和17%，而锥体5(5(C))和部分锥体5(5(PC))进行立体选择性氧化，得到RCCC和Rcct异构体，在脱苄基后，分别得到56%和28%的RCCC和Rcct异构体，基于5用X-射线单晶衍射法测定了其亚磺基的分布和苯酚单元的构象。还报道了2(5(C)，5(PC)，5(1，2-A)和5(1，3-A))的四种构象异构体的合成。
All four stereoisomers of p-tert-butylsulfinylcalix[4]arene [4(rccc), 4(rcct), 4(rctt), and 4(rtct)], arising from the disposition of the four sulfinyl groups with respect to the mean plane of the four bridging sulfur atoms, have been prepared via oxidation of p-tert-butylthiacalix[4]arene (2) or its tetra-O-benzyl ethers 5 of defined conformations. Thus, treatment of 2 with 4.4 molar equiv of NaBO(3).4H(2)O gave the rtct and rctt isomers in 27% and 17% yields, respectively, while oxidation of cone 5 (5(C)) and partial cone 5 (5(PC)) proceeded stereoselectively to give, after debenzylation of the resulting tetrasulfoxides 12 and 15, the rccc and rcct isomers in 56% and 28% yields, respectively, based on 5. The sulfinylcalix[4]arenes 4 were treated with iodomethane in the presence of a base to give the corresponding tetramethyl ethers 16, the structures of which in regard to the disposition of the sulfinyl groups and the conformation of the phenol units were determined by X-ray crystallography. Also reported is the synthesis of all four conformational isomers of tetra-O-benzyl ether of 2 (5(C), 5(PC), 5(1,2-A), and 5(1,3-A)).