Chiral recognition between a substituted cyclooctatetraene dianion and a half crown ether substituted with ibuprofen.
(S)-Verbenol was substituted onto cyclooctatetraene (COT) via an ether linkage. In tetrahydrofuran (THF), Cs(+) or Na(+) counterions are tightly ion associated with the verbenoxy-COT dianion. A cosolvent, consisting of an ibuprofen unit connected to a half crown ether, was added to the verbenoxy-COT(2)(-),M(+)(2) solutions. The intimate interaction between the chiral cosolvent (ibuprofoxymethoxyethoxyethane) and the ion-associated counterion (either Na(+) or Cs(+)) forces a chiral recognition between the verbenoxy moiety and the ibuprofoxy moiety. When a molar excess of the cosolvent is present in the dianion THF solution, separation of the cosolvent associated with the verbenoxy-COT(2)(-),M(+)(2) complex from the uncomplexed cosolvent allows partial resolution of the enantiomers of ibuprofoxymethoxyethoxyethane.
Stevenson
C D
CD
Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, USA. Stevenson@xenon.che.ilstu.edu
Cashion
D K
DK
D000465:Algorithms; D004578:Electron Spin Resonance Spectroscopy; D004988:Ethers, Cyclic / Q000138:chemical synthesis / Q000737:chemistry*; D007052:Ibuprofen / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013237:Stereoisomerism
D004988:Ethers, Cyclic; D007052:Ibuprofen