描述了一种通过金(I)催化的1-芳基-2-炔丙基环己二-2-烯醇的环异构化反应轻松合成四氢苯并[ b ]呋喃的方法。建议该转化过程通过金(I)催化的叔烯丙醇重排进行,得到仲烯丙基醇,该仲烯丙醇经过羟基5-exo-dig加成到金(I)活化的炔烃上以生成乙烯基金种类。所得到的乙烯基金中间体的原型脱脂,然后进行芳构化,得到四氢苯并[ b ]呋喃。
The diacetate of meso-2-(2-propynyl)cyclohexane-1,2,3-triol was efficiently asymmetrized by hydrolysis with Candida antarctica lipase to give the corresponding mono-acetate in enantiomerically pure form, which was used as the starting material for the total synthesis of aquayamycin. Application of the protocol to the related cyclohexanetriols is also described.
Photoinduced electron transfer (PET) reactions of α-cyclopropyl-substituted ketones and triethylamine (TEA) were used to initiate the cyclopropylcarbinyl-homoallyl rearrangement. The intramolecular cyclization reaction onto triple bonds was performed yielding bicyclic and spirocyclic compounds. Furthermore, in some preliminary studies it was shown that even intramolecular aromatic substitutions are
Tunable Cyclization Strategy for the Synthesis of Zizaene-, <i>allo</i>-Cedrane-, <i>seco</i>-Kaurane-, and <i>seco</i>-Atesane-Type Skeletons
作者:Qianqian Yang、Wenjing Ma、Gaopeng Wang、Wenli Bao、Xiaoshu Dong、Xuefeng Liang、Lizhi Zhu、Chi-Sing Lee
DOI:10.1021/acs.orglett.7b02610
日期:2017.10.6
A versatile Lewis acid-mediatedcyclization strategy has been developed for selectively establishing zizaene-, allo-cedrane-, seco-kaurane-, and seco-atesane-type skeletons. The zizaene- and seco-atesane-type skeletons can be obtained in a cascade manner, which involves Diels–Alder reaction of cyclic enones with bis-silyloxy dienes and carbocyclization of yne–enolates through Lewis acid dependent 5-
Construction of Angularly Fused Tricyclic Compounds via Photo‐induced Radical Cascade Cyclization
作者:Mengqin Hu、Wei Cao、Zhen Wang、Yan Hao、Ganxing Huang、Yuqiao Zhou、Song Qin、Shaomin Fu、Bo Liu
DOI:10.1002/cjoc.202300246
日期:2023.10
(PET) of silyl enol ethers has been employed to synthesize several fused ring systems. However, the method has limited applicability due to its narrow substrate scope, low product yields, unsatisfactory stereo- and regioselectivity. Herein, we report a PET-triggered cascade reaction of silyl enolates that leads to the formation of angularly fused tricyclic scaffolds. The reaction exhibits broad substrate
硅烯醇醚的光诱导电子转移(PET)已被用来合成多种稠环系统。然而,由于底物范围窄、产物收率低、立体选择性和区域选择性不理想,该方法的适用性受到限制。在此,我们报道了 PET 触发的甲硅烷基烯醇化物级联反应,导致形成有角度稠合的三环支架。该反应表现出广泛的底物范围和优异的立体选择性。通过 DFT 计算和构象分析阐明了该级联反应的区域选择性和立体选择性。
2,3a,5,6,7,7a-Hexahydro-3h,4h-benzothiophene-3,4-dione and cyclopenta [b]-tetrahydrothiophene-3,4-dione enolate anions as synthetic equivalents to cyclohex-2-enone and cyclopent-2-enone c-2-carbanions.
作者:Pier Giovani Baraldi、Barco Achille、Benetti Simoneta、Pollini Gian Piero、Zanirato Vinicio