Synthetic routes to pyrrolizine-1,5-dione derivatives by flash vacuum pyrolysis of amidomethylene derivatives of Meldrum's acid
作者:Hamish McNab、Mark Morrow、Simon Parsons、David A. Shannon、Kirsti Withell
DOI:10.1039/b911951e
日期:——
Methoxymethylene Meldrum's acid 1 reacts with 5- and 6-membered lactams in refluxing acetonitrile to give the N-substituted products 9–15. If the reactions are continued for extended times, the Meldrum's acid derivatives decompose to provide enamidoesters e.g.22–24. Flash vacuum pyrolysis of the 5-membered ring products 9–13 provides reasonable yields of the fused pyrrolones 31–35. The constitution
甲氧基亚甲基 麦芽糖酸 1在回流下与5元和6元内酰胺反应乙腈得到N取代的产物9-15。如果反应持续较长时间,则Meldrum的酸衍生物会分解为en烯酸酯,例如22-24。5元环产物9-13的快速真空热解提供了稠合吡咯烷酮31-35的合理收率。产品的结构通过X射线晶体结构支撑10,12,19,32和34。