对称双吡咯甲烷的合成与分子内氢键的研究

５－甲基吡咯－２－羧酸酯在磺酰氢，溴或四乙酸铅作用下，生成相应的在５－甲基上含取代基的产物，后者不经分离不便可自缩合得标题化合物，核磁共振氢谱研究和分子构象木匠，当３，３位的取代基为甲酸（酯）基或乙酸（酯）基时，可形成３，３位酯基与另一吡咯环上的氮氢之间的分子内氢键，而３，３位是其它取代基，如乙酰基，丙酸（酯）基，丁酸（酯）基时不能形成类似的分子内氢键。

Synthesis and Intramolecular Hydrogen Bonding ofSymmetric Dipyrrylmethanes

The title compounds were prepared by converting ethyl 5-methylpyrrole-2-car boxylates into corresponding 5-methyl substituted pyrroles oxydized by surfuryl chloride,bromine,or lead tetraacetate, and then self-condensed without separation and purification.The 1H NMR analysis and molecular conformation computation revealed that strong in tramolecular hydrogen bondings exist in dipyrrylmethane 4b and 4c (3 . 3' substituents are for mate and acetate esters),while very weak or no intramolecular hydrogen bonding exists in other dipyrrylmethanes.