Synthesis of 2,5-Disubstituted Pyrroles and Pyrrolidines by Intramolecular Cyclization of 6-Amino-3-keto Sulfones
作者:Simonetta Benetti、Carmela De Risi、Paolo Marchetti、Gian P. Pollini、Vinicio Zanirato
DOI:10.1055/s-2002-20025
日期:——
-unsaturated keto sulfones which have been conveniently utilized as precursors of both aromatic and non-aromatic 2,5-disubstituted five-mem- bered heterocyclic compounds. While 2,5-disubstituted pyrroles are efficiently formed by cyclodehydration of the starting materials, 2,5-disubstituted pyrrolidines and pyrrolenines could be obtained by prior reduction of the conjugated double bond followed by acid-
4-((4-甲基苯基)磺酰基)-1-(三苯基正膦亚基)丁-2-酮(1)与N-保护-氨基醛的Wittig反应提供了N-保护-氨基-,-不饱和酮砜用作芳香族和非芳香族 2,5-二取代五元杂环化合物的前体。虽然 2,5-二取代吡咯可通过起始材料的环化脱水有效地形成,但 2,5-二取代吡咯烷和吡咯啉可通过预先还原共轭双键然后酸或碱介导的环化来获得。整个序列所需材料的现成可用性使该方法成为生成芳香族和饱和 2,5-二取代五元杂环化合物的便捷方法。