94411-74-2Relevant academic research and scientific papers
Pyrans, 100. - 5,6-Dihydro-2H-pyran-3(4H)-one as a Building Unit for the Synthesis of Pyran-annulated Heterocyclic Compounds
Eiden, Fritz,Wanner, Klaus Th.
, p. 1759 - 1777 (2007/10/02)
Only in a few cases 5,6-dihydro-2H-pyran-3(4H)-one (3) reacts regioselectively with ortho-substituted phenylcarbonyl compounds to form pyran-annulated heterocyclic compounds like the pyranoquinoline 7c.Better results are obtained in reactions involving the enamine 15d derived from 3, the silyl enol ether 18 and the lithium enolate 14 derived from 18.These pyran derivatives with 2,3- or 3,4-double bonds are well suited for successful synthesis of 2-or 4-substituted 3-pyranones such as 2, 21a, 21b, 23a - c, 26a - c, 31a - c, 32, and 35a - c.They also allow to synthesize pyrano- or -quinolines, -quinolones, -chromones, and -thiochromones 6a, 30a - c, 38a - d.
