Selective synthesis of natural and unnatural 5,6-disubstituted 2(2H)-pyranones via iodolactonization of 5-substituted (Z)-2-en-4-ynoic acids
作者:Fabio Bellina、Matteo Biagetti、Adriano Carpita、Renzo Rossi
DOI:10.1016/s0040-4020(01)00139-9
日期:2001.4
-2(5H)-furanones and 6-substituted 5-iodo-2(2H)-pyranones in which these last compounds are the major products. The 5-iodo-2(2H)-pyranones, which are easily separated chromatographically from the corresponding regioisomers, are able to undergo Stille-type reactions with a variety of organotin compounds to give 5,6-disubstituted 2(2H)-pyranones in moderate to good yields. One of these compounds, i.e
5-取代的(Z)-2-en-4-壬酸与CH 3 CN中的碘和NaHCO 3或与CH 2 Cl 2中的ICl反应,得到(E)-5-(1-碘亚烷基)-2的混合物(5 H)-呋喃酮和6-取代的5-碘-2(2 H)-吡喃酮类化合物是其中的主要产物。5-碘-2-(2 H)-吡喃酮很容易从色谱上从相应的区域异构体中分离出来,能够与多种有机锡化合物进行Stille型反应,从而生成5,6-二取代的2(2 H)-吡喃酮的产量中等至良好。这些化合物之一,即5-(1-丁炔基)-2(2 H)-吡喃酮已被用作真菌培养物LL-11G219产生的两种物质的直接前体,它们起着雄激素配体的作用,即(Z)-5-(1-丁烯基)-6-甲基-2(2 H)-吡喃酮和5-丁基-6-甲基-2(2 H)-吡喃酮。