Generation of Cyclic Ketene-<i>N</i>,<i>X</i>-Acetals (X = O, S) from 2-Alkyl-1,3-oxazolines and 2-Alkyl-1,3-thiazolines. Reactions with Acid Chlorides, 1,3-Diacid Chlorides and<i>N</i>-(Chlorocarbonyl) Isocyanate
作者:Aihua Zhou、Charles U. Pittman Jr.
DOI:10.1055/s-2005-918499
日期:——
reacted with monoacid chlorides, diacid chlorides, triacid chlorides. A series of these carbon-carbon bond-forming reactions and cyclizations to both substituted 2,3-dihydrooxazolo[3,2-a]pyridine-5,7-diones and 2,3-dihydrothiazolo[3,2-a]pyridine-5,7-diones proceeded under mild reaction conditions. Cyclic ketene-N,X-acetal intermediates play important roles in all these reactions. Related cyclizations
2-烷基-l,3-恶唑啉、2-烷基-l,3-噻唑啉以及衍生自它们的相应环状乙烯酮-N,X-缩醛(X = O, S)与一元酰氯、二酰氯反应,三酰氯。一系列这些碳-碳键形成反应和环化反应生成取代的 2,3-二氢恶唑并[3,2-a]吡啶-5,7-二酮和 2,3-二氢噻唑并[3,2-a]吡啶- 5,7-二酮在温和的反应条件下进行。环状烯酮-N,X-缩醛中间体在所有这些反应中发挥重要作用。与 N-(氯羰基) 异氰酸酯的相关环化反应形成取代的 2,3-二氢恶唑并[3,2-c]嘧啶-5,7-二酮和 2,3-二氢噻唑并[3,2-c]嘧啶-5,7-二酮.