Diels-Alder Reactions of 6-Alkyl-3,5-dichloro-2<i>H</i>-1,4-oxazin-2-ones with Alkynes: Synthesis of 3,5-Disubstituted 2,6-Dichloropyridines
作者:Lieven Meerpoel、Geert Deroover、Koen Van Aken、Gerrit Lux、Georges Hoornaert
DOI:10.1055/s-1991-26570
日期:——
The Diels-Alder reaction of 6-alkyl-3,5-dichloro-2H-1,4-oxazin-2-ones 1 with different types of acetylenic compounds 2 is shown to be a versatile method for the generation of variously substituted 2,6-dichloropyridines. In most cases a high degree of regioselectivity and a high yield of 3,5-disubstituted 2,6-dichloropyridines 3 is obtained.
Synthesis of 3,5-dihalogeno-2H-1,4-oxazin-2-ones from cyanohydrines
作者:L. Meerpoel、G. Hoornaert
DOI:10.1016/s0040-4039(00)99196-2
日期:——
The title compounds were obtained on treatment of cyanohydrines of aliphatic and aryl aldehydes with oxalyl chloride or bromide in chlorobenzene at 90°C. Evidence for their structure is given by their spectroscopic data and by the Diels Alder reaction of a and g with acetylenic dienophiles to yield substituted pyridines. Cycloaddition was also observed with ethene.