The interaction of ptertbutylthiacalix[4]arene with N,Ndiethylchloroacetamide was stud ied in the presence of alkali metal carbonates in acetone. Three stereoisomers, viz., cone, partial cone, and 1,3alternate, of the tetraamide derivative of thiacalixarene substituted at the lower rim were synthesized selectively using the template effect of alkali metal cations, as well as a complex of the 1,3alternate stereoisomer with potassium chloride. ... إقراء المزيد

The three conformations of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis[(benzoyl)methoxy]-2,8,14,20-tetrathiacalix[4]arene 1: cone, partial cone and 1,3-alternate, were prepared by the treatment of 5,11,17,23-tetra-tert-butyl-2,8,14,20-tetrathiacalix[4]arene25,26,27,28-tetraol (TCA) with a-bromo acetophenone in the presence of appropriate alkali carbonate M2CO3 (M¼Na, K, Cs) as base catalyst in acetonitrile. Structure of the conformers were established by 1H NMR, 1H–1H COSY, 1D NOE, 2D ROESY and X-ray experiments. The alkali cation binding ... إقراء المزيد