A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction
作者:Christian Eidamshaus、Roopender Kumar、Mrinal K Bera、Hans-Ulrich Reissig
DOI:10.3762/bjoc.7.108
日期:——
reaction of alkoxyallenes, nitriles and carboxylic acids to provide beta-methoxy-beta-ketoenamides which are transformed into 4-hydroxypyridines in a subsequent cyclocondensation. The process shows broad substrate scope and leads to differentially substituted enantiopure pyridines in good to moderate yields. The preparation of diverse substituted lactic acid derived pyrid-4-yl nonaflates is described
描述了在 2 位和 6 位具有立体侧链的高度官能化 4-羟基吡啶衍生物的实用方法。所提出的两步法利用烷氧基丙二烯、腈和羧酸的多组分反应来提供 β-甲氧基-β-酮烯酰胺,其在随后的环缩合反应中转化为 4-羟基吡啶。该过程显示出广泛的底物范围,并以良好到中等的产率产生差异取代的对映体纯吡啶。描述了多种取代乳酸衍生的 pyrid-4-yl nonaflates 的制备。提供了多组分反应的假定机制的其他证据。