Samarium Diiodide in the Synthesis of Medium-Sized Rings - Carbocycles and Heterocycles by Intramolecular Addition of Samarium Ketyls to Alkynes
作者:Hans-Ulrich Reissig、Alexandra Hölemann
DOI:10.1055/s-2004-835657
日期:——
A series of alkynyl-substituted ketones and aldehydes was subjected to samariumdiiodide in the presence of HMPA to study the scope and limitations of their ketyl-alkyne coupling. Seven- and eight-membered heterocycles such as 4, 6, 8, 25, 27, 29, 33, and 35 could be isolated in moderate to good yields. Other cyclization products were isolated in low yields only. The efficacy of the reductive cyclization