A new and efficient method for the preparation of N-protected 5- and 2-substituted 3-bromopyrroles 15 and 16 via acid-catalyzed cyclization of the corresponding acetylenic ketones 6 and acetylenic acetals 14 has been found (Scheme 3). Using this methodology, rapid and quite general access to highly substituted pyrroles, which are known to exhibit a number of interesting biological activities, has been established.
发现了一种新的高效方法,用于制备N-保护的5-和2-取代的
3-溴吡咯15和16,该方法通过酸催化的环化反应,将相应的炔酮6和炔
缩醛14进行合成(图式3)。利用这种方法,已成功实现对高度取代的
吡咯的快速且广泛的合成,这些
吡咯已知具有多种有趣的
生物活性。