Macrocyclic 14-Membered Ring Diketal Dilactams: Evaluation of their Divalent Cation Binding Properties

The binding abilities of a new class of 14-membered ring ligands bearing diketal dilactam functions were explored by UV-visible spectrophotometry. Their formation constants, determined in THF solution, showed appreciable complexation with divalent cations (stability order: Sr²⁺≥Ca²⁺>Zn²⁺≥Mg²⁺>Ba²⁺) whereas no association was observed with monovalent cations. The stoichiometry of the complexes formed was essentially 1:1 although sometimes a low percentage (<10%) of 1:2 (cation–ligand) species was detected. The corresponding formation constants determined by computation (STAR program) were in the range 1.5<log?β ¹¹<4.8 and 4.4<log?β ¹²<7.1. They depend significantly on the nature of the substituents. In addition, solvent extractions carried out in a water–chloroform system showed the highest constants (log K ^ex) for the most substituted macrocycles 7b and 7c (norephedrine series) with a lipophilic skeleton.     

甲基磺酸催化合成季戊四醇双缩醛(酮)

季戊四醇双缩醛、双缩酮化合物在工业和有机合成中应用广泛。工业上常作为增塑剂、抗氧剂、杀虫剂和表面活性剂的消泡剂,在有机合成中用来合成有生理活性的物质和作为醛、酮的保护基团。季戊四醇双缩醛、酮的合成通常在酸性条件下进行,已报道的催化剂有质子酸:如盐酸[1]、硫酸[     

微波辐射条件下季戊四醇杂二缩醛(酮)的合成

在微波辐射下, 以活性炭负载磷钨酸为催化剂, N,N-二甲基甲酰胺为溶剂, 将季戊四醇与醛(酮)缩合得到季戊四醇单缩醛(酮), 然后再与另一种醛缩合合成了9种季戊四醇杂二缩醛(酮). 产物经过元素分析, IR和¹H NMR表征.