A new method for the synthesis of n-(3-acyloxypropyl)-substituted six- to thirteen-membered alkan-n-olides was developed. The method is based on the H2SO4-catalyzed reactions of oxabicycloalkenes, obtained from 2-(3-acetoxypropyl)cycloalkanes, with H2O2 and formic or acetic acid. The method includes the subsequent transformations of oxabicycloalkenes; into bicyclic hydroperoxides, peroxy ethers, and, at the final stage, into target lactones formed in 56-71% yields. These transformations are carried as a one-pot reaction.
A new method for the synthesis of n-(3-acyloxypropyl)-substituted six- to thirteen-membered alkan-n-olides was developed. The method is based on the H2SO4-catalyzed reactions of oxabicycloalkenes, obtained from 2-(3-acetoxypropyl)cycloalkanes, with H2O2 and formic or acetic acid. The method includes the subsequent transformations of oxabicycloalkenes; into bicyclic hydroperoxides, peroxy ethers, and, at the final stage, into target lactones formed in 56-71% yields. These transformations are carried as a one-pot reaction.
A rearrangement of 1-hydroperoxy-2-oxabicycloalkanes into lactones of ω-acyloxy-(ω-3)-hydroxyalkanoic acids related to the Criegee reaction
作者:Yuri N Ogibin、Alexandre O Terent'ev、Alexandre V Kutkin、Gennady I Nikishin
DOI:10.1016/s0040-4039(01)02368-1
日期:2002.2
1-Hydroperoxy-2-oxabicyclo[n.4.0]alkanes (n=3, 4, 5 and 10) on heating with formic or acetic acid containing a catalytic amount of sulfuric acid undergo a rearrangement into lactones of ω-acyloxy-(ω-3)-hydroxyalkanoic acids by a mechanism related to the Criegee reaction.
在与含有催化量硫酸的甲酸或乙酸加热下,将1-羟过氧-2-氧杂双环[ n .4.0]烷烃(n = 3、4、5和10)进行重排,使其成为ω-酰氧基-(ω -3)-羟基链烷酸是通过与Criegee反应有关的机理而形成的。
A cheap metal catalyzed ring expansion/cross-coupling cascade: a new route to functionalized medium-sized and macrolactones
An efficient alkoxyl radical-triggered ringexpansion/cross-coupling cascade was developed under cheap metal catalysis. Through the metal-catalyzed radical relay strategy, a wide range of medium-sized lactones (9–11 membered) and macrolactones (12, 13, 15, 18, and 19-membered) were constructed in moderate to good yields, along with diverse functional groups including CN, N3, SCN, and X groups installed
在廉价金属催化下开发了一种有效的烷氧基自由基触发的扩环/交叉偶联级联。通过金属催化的自由基中继策略,以中等至良好的产率构建了各种中型内酯(9-11元)和大环内酯(12、13、15、18和19元),以及多种同时安装的功能组包括CN、N 3、SCN和X组。密度泛函理论(DFT)计算表明,环烷基-Cu(III)物质的还原消除是交叉偶联步骤更有利的反应途径。基于实验和DFT的结果,提出了用于该串联反应的Cu( I )/Cu( II )/Cu( III )催化循环。
A photoinduced copper-catalyzed alkoxyl triggered C−C bond cleavage/aminocarbonylation cascade is presented. Through adjusting the structure of alkoxyl radical precursors, functionalized lactones and keto-amides were synthesized with good yields and excellent functional group tolerance under redox-neutral conditions. Notably, this protocol enables the integration of lactone fragments with many amine