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The synthesis of four Cn symmetric macrocyclic lactams cyclo-[NHCH2-CH= CH-CH2-CO] n (1, n= 2; 2, n= 3; 3, n= 4) and cyclo-[NH-CH2-CH2-CH= CH-CO] 3 (4) has been achieved by two approaches. A linear route leads to precursors that are subsequently macrocyclized in a separate step. The second, convergent approach relies on the symmetry of the targets: it includes suitably activated subunits, which are subjected to macrocyclization conditions. The subunits first oligomerize, then cyclize to form either pure macrolactams or mixtures. The macrolactam units 1, 2 and 4 stack on top each other through weak interactions (hydrogen bond and van der Waals), to form endless square, rectangular and triangular prisms, respectively. These stacks are further packed side by side in crystals grown from isotropic media. The overall dipoles in the crystals from lactams 1 and 4, which result mostly from the alignment of …