ml��pߺ��ll1yN�(��tAe���>�v�>���h~c��L���}+{�鐾&��M�6c:xB���Z��+X�W�%C��tIpf/�=`�^|$�NUs�{��ߞٟ�Ʃ}:]��S���zґ0X1�(o`�A��g����=����DX��h/�r�0)c8������� �����b����w����)c��{g�8{�2��Ż�q �v�[�v��a+Nٍ1����R�p0p��=2OI����}�*���� �ј�Ɩ�da����B�ћE��lj�1�{P�p���z�� Gk¤g��!��������m1�pp�}T��Nm������6��?���(fL0f���ڊ2�c�d�0��-�m�ڒb�c��;�ϒR�����0��-���kAcR[tĘ�����6uN`�1t_`�6�\� �k�A����"F�1�w�p坴L� c6wr�|ټF�+�Q�0f3F�lF"��7���ڌAF���I���7C;d`�)�� �6���^��X� ��@���-�9�[�D�w��W?�pe���FG�D1�{�aH@j7���(a$��.F ���Fx��ș�Zt8D+���sڵȃ �g]r@�!g��/A��f�{���- ��I #��5;b$�� H�`�C�ht�H�} � ɣ�1�)���Y�M�0 In all cases the Ref. Crown ethers are named using both the total number of atoms in the ring and the number of oxygen atoms. These monosaccharide‐based chiral macrocycles were tested as phase transfer catalysts in a few asymmetric reactions. Fetching data from CrossRef. D. E. Fenton, D. Parkin and R. F. Newton, Instructions for using Copyright Clearance Center page. Starting from the commercially available 1,4-cyclohexadiene 3, epoxide 4 was obtained through reaction with meta-chloroperoxybenzoic acid (mCPBA). is available on our Permission Requests page. Thus 18-crown-6 is an 18-membered ring with six oxygen atoms (part (a) in Figure 18.7.1 ). 3, Budapest 1111, Hungary. "crown" refers to oxacrowns. Alkali and alkaline-earth metal complexes of these ligands have been prepared. and you may need to create a new Wiley Online Library account. • The most common crown ethers are oligomers of ethylene oxide. %PDF-1.2 %����
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A method of separating crown ethers based on their preferential complexation of barium is discussed. Crown Ethers.
Go to our contained in this article in third party publications The synthesis of crown ethers 1 and 2 is based on a general strategy, as previously published for the synthesis of DC18C6,15 shown in Scheme 1. If you are not the author of this article and you wish to reproduce material from
Learn about our remote access options, Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Budapest, Hungary. The syntheses of adrenaline-15-crown-5 and adrenaline-18-crown-6 starting from acetovanillone are reported, together with the properties of these compounds. 18-Crown-6 negative charge concentrated in cavity inside the molecule O O O O O O. The xylal‐based crown compounds proved to be efficient catalysts in a few liquid‐liquid phase reactions. It was found that the substituents in the aromatic ring of the chalcone and the α‐chloroacetophenone had an influence on the enantioselectivity.