通过微波辅助聚磷酸乙酯(PPE)促进的ω-硫代酰胺醇的闭环反应,开发了一种高效且通用的合成2-取代的噻唑啉和5,6-二氢-4 H -1,3-噻嗪的方法。环化反应涉及S N 2型机理,具有反应时间短,产率高和可预测的立体化学结果的优点。无环前体是通过改进的二酰化-硫磺化-皂化顺序,从市售的ω-氨基醇中以高收率制备的。整个过程无金属且操作简单。
ketenes in the Staudingerreaction. On the basis of the reactions of S-phenyl diazothioacetate with imines under the catalysis of Rh 2 (OAc) 4 a method for the synthesis of 3-phenylthio β-lactam derivatives has been developed previously. In this paper, a more convenient and improved procedure was achieved, which simplified the synthesis of S-phenyl diazothioacetate and made the reaction work well without
作者:Ajay K. Bose、M.S. Manhas、J.M. van der Veen、S.G. Amin、I.F. Fernandez、K. Gala、R. Gruska、J.C. Kapur、M.S. Khajavi、J. Kreder、L. Mukkavilli、B. Ram、M. Sugiura、J.E. Vincent
DOI:10.1016/s0040-4020(01)88885-2
日期:1981.1
A safe and convenient method is described for the synthesis of α-amido-β-lactams starting with glycine and an azomethine. The amino group of glycine is protected by reaction with a β-dicarbonyl compound following the method of Dane etal. and the carboxyl group is activated through the formation of a mixed anhydride or an active ester. Condensation between these glycine derivatives and acyclic or cyclic
Synthesis of 3-Alkoxy/Aryloxy-β-lactams Using Diazoacetate Esters as Ketene Precursors Under Photoirradiation
作者:Jiaxi Xu、Hengzhen Qi、Zhanhui Yang
DOI:10.1055/s-0030-1259485
日期:2011.3
imines from their trans-isomers into syn-isomers under UV irradiation. The reported method represents a metal-free and neutral approach for the synthesis of 3-alkoxy/aryloxy-β-lactams. diazoacetate - imine -ketene- β-lactam - photoirradiation - Staudinger reaction
Kondensierte Azetidinone, 9. Mitt.: Cepham-Analoge und Cepham-Isomere durch Keten-Cycloimin-Cycloaddition
作者:F. Moll、H. J. Wieland
DOI:10.1002/ardp.19753080703
日期:——
Durch [2 + 2]‐Cycloaddition von Diphenylketen an 2‐Phenyl‐Δ1‐piperidein wurde das carbocyclische Cepham‐Analoge 3 und daneben das Diphenylacetyl‐2‐phenyl‐Δ2‐piperidein 4 erhalten. Mit Dichlorketen entstand als Hauptprodukt N‐Dichloracetyl‐2‐phenyl‐Δ2‐piperidein. Die Cycloaddition von Ketenen an 5,6‐Dihydro‐1,3‐oxazine ergab die sauerstoffhaltigen Cepham‐Analogen 7 und 8, die Cycloaddition an 5,6‐Dihydro‐1
Thionation ofN-(?-Halogenoalkyl)-Substituted Amides withLawesson's Reagent: Facile Synthesis of 4,5-Dihydro-1,3-thiazoles and 5,6-Dihydro-4H-1,3-thiazines
作者:Yasuhiro Kodama、Mayuko Ori、Takehiko Nishio
DOI:10.1002/hlca.200590000
日期:2005.2
The thionation and cyclization of N-(ω-halogenoalkyl)-substitutedamides (and related compounds) with Lawesson's reagent (LR=2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide) has been investigated. Treatment of the amides 1 with LR gave the corresponding thioamides 2 in moderate to good yields (Table). The latter, upon treatment with base, afforded, either in a separate step or in