The classical Ritter reaction on γ-hydroxy-α,β-alkynoic esters produced γ-N-acylamino-β-keto esters or ethyl 5-oxazoleacetates using alkyl or aryl nitriles, respectively. The γ-N-acylamino-β-keto esters resulting from alkyl nitriles are useful intermediates in the synthesis of a variety of building blocks. We also show that these can be converted into ethyl 5-oxazoleacetates using an additional step
[EN] FUSED TRICYCLIC DERIVATIVE, PREPARATION METHOD THEREFOR, AND PHARMACEUTICAL APPLICATION THEREOF<br/>[FR] DÉRIVÉ TRICYCLIQUE CONDENSÉ, SON PROCÉDÉ DE PRÉPARATION ET SON APPLICATION PHARMACEUTIQUE<br/>[ZH] 并三环类衍生物、其制备方法及其在医药上的应用
Metal-free annulative hydrosulfonation of propiolate esters: synthesis of 4-sulfonates of coumarins and butenolides
作者:Rodney A. Fernandes、Ashvin J. Gangani、Rupesh A. Kunkalkar
DOI:10.1039/c9nj06438a
日期:——
An efficient metal-free and cost-effective method for the synthesis of coumarin and butenolide 4-sulfonates has been developed involving addition of sulfonic acids to ethyl propiolates followed by lactonization.
A Short, Novel Approach to 2,3,4a,5-Tetrahydro-1<i>H</i>-pyrazino[1,2-<i>a</i>]quinoline-4,6-diones
作者:Ronald C. Bernotas
DOI:10.1055/s-2004-831308
日期:——
An expeditious route to constrained arylpiperazinones has been developed. The key reaction formed the tricyclic system in one-pot via a 1,4-addition-lactamization-aromatic substitution sequence. Four examples were prepared.