Two different 1, 3-Distal thiacalix[4]arenas were prepared by the reaction of thiacalix[4]arenewithphenacyland/orp-nitrophenacylbromideinacetoneoracetonitrile in the presence of dry CsOH. The prepared 1, 3-distal disubstituted thiacalixarenes afforded two pairs of diastereomers upon brominating in chloroform. The obtained diastereomers were separated by fractional crystallization in a mixture dichloromethane-acetone إقراء المزيد