Islam, Md. Monarul Hirotsugu, Tomiyasu Thuery, Pierre Matsumoto, Taisuke Tanaka, Junji Elsegood, Mark Redshaw, Carl Yamato, Takehiko Synthesis and conformational studies of calixarene analogue chiral [3.3.1]metacyclophanes Trihydroxy[3.3.1]metacyclophane, which can be regarded as an unsymmetrical or incomplete "homocalix[3]arene", has been prepared from rimethoxy[3.3.1]metacyclophane by demethylation with trimethylsilyl iodide in MeCN. Di-O-methylation at the lower rim of trihydroxy[3.3.1]metacyclophane in the presence of K2CO3 in acetone afforded a novel, inherently chiral calixarene-analogue, namely a macrocyclic [3.3.1]metacyclophane, possessing C1 symmetry. The inherent chirality of the two conformers was characterized by <sup>1</sup>H NMR spectroscopy by addition of an excess of Pirkle's chiral shift reagent [(S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol], which caused a splitting of the OMe group and AB patterns corresponding to the methylene protons. Metacyclophanes;Macrocycles;Calixarenes;Intramolecular hydrogen bonding;Oemethylation;Chirality;Chemical Sciences not elsewhere classified 2015-09-07
    https://repository.lboro.ac.uk/articles/journal_contribution/Synthesis_and_conformational_studies_of_calixarene_analogue_chiral_3_3_1_metacyclophanes/9394769