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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 10, Number 6
BKCSDE 10(6)
June 20, 1989 

 
Title
Cyclic Host Having Double Bonds as Bridging Units
Author
Kyung-Soo Paek*, Donald J. Cram
Keywords
Abstract
Terphenyl dialdehyde 6 was obtained in 17.4% overall yield through oxidative coupling, methylation, and bisformylation reactions starting from p-cresol, and then coupled intermolecularly using McMurry reaction to give 22-membered macrocylic host 7 in 14.4% yield. In crystal structure host 7 has C2v symmetry with cis-cis configuration of two double bonds. Four methoxy groups adjacent to double bonds and the other two methoxy groups are directed opposite side, forming a cavity which can nest a guest. The cavity is filled by two inward-turned methyl groups out of four methoxy groups adjacent to double bonds. The kinetically controlled reaction mechanism leading to cis product was proposed. The cation binding properties of 7 were obtained using picrate extraction experiment from D2O into CDCl3 at 25℃. All the spherical cations (from Li+ to NH4+) are complexed with free energies of 7.3±0.3 kcal/mol.
Page
568 - 572
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