Six opticallyactive α-hydroxyl-β,γ-unsaturated acid esters 1a to 1f were synthesised, and they are significant moieties of the cerebrosides. The chiral intermediate alkynol 4 prepared by catalytic asymmetric addition had 99% ee, and which was converted into the target compounds 1a to 1f with high enantiomeric purity.
Olefin Cross-Metathesis as a Tool in Natural Product Degradation. The Stereochemistry of (+)-Falcarindiol
作者:Anokha S. Ratnayake、Thomas Hemscheidt
DOI:10.1021/ol027033z
日期:2002.12.1
olefin cross-metathesis using Grubbs' second generation catalyst and ethylene gas to degrade falcarindiol to the symmetrical 1,9-decadiene-4,6-diyne-3,8-diol. The reaction is completely selective for net removal of the aliphatic side chain. Degradation of (+)-falcarindiol from Tetraplasandra hawaiiensis yields a meso product as shown by chiral HPLC. Hence, (+)-falcarindiol from this source has a (3R,8S)-configuration
Stereoselective Synthesis of the Isomers of Notoincisol A: Assigment of the Absolute Configuration of this Natural Product and Biological Evaluation
作者:Lukas Rycek、Vincenzo Ticli、Jakob Pyszkowski、Simone Latkolik、Xin Liu、Atanas G. Atanasov、Theresa Steinacher、Rudolf Bauer、Daniela Schuster、Verena M. Dirsch、Michael Schnürch、Margot Ernst、Marko D. Mihovilovic
DOI:10.1021/acs.jnatprod.8b00439
日期:2018.11.26
proliferator-activated receptor gamma) as a prominent receptor related to inflammation is reported. Only the natural isomer was found to activate the PPARγ receptor, and this phenomenon could be explained based on molecular docking studies. In addition, the pharmacological profiles of the isomers were determined using the GABAA (gamma-aminobutyric acid A) ionchannelreceptor as a representative target
A fine addition! A highlyenantioselective and efficient procedure for the amino‐alcohol–zinc‐catalyzedaddition of trimethylsilylacetylene to aromatic, α,β‐unsaturated, and aliphatic aldehydes has been developed (see scheme; R=aryl, alkynyl, or alkyl; TMS=trimethylsilyl; TBDMS=tert‐butyldimethylsilyl). The present protocol was successfully applied in the concise synthesis of the natural products marine
很好的补充!已开发出一种高度对映选择性和高效的程序,用于氨基醇锌催化的三甲基甲硅烷基乙炔加成到芳族,α,β-不饱和和脂肪族醛中(见方案; R =芳基,炔基或烷基; TMS =三甲基甲硅烷基; TBDMS =叔丁基二甲基甲硅烷基)。本协议已成功地应用于天然产物海洋炔醇和法卡林二醇的简明合成中。
Catalytic<i>Z</i>-Selective Cross-Metathesis with Secondary Silyl- and Benzyl-Protected Allylic Ethers: Mechanistic Aspects and Applications to Natural Product Synthesis
作者:Tyler J. Mann、Alexander W. H. Speed、Richard R. Schrock、Amir H. Hoveyda
DOI:10.1002/anie.201302538
日期:2013.8.5
Get me a Z (olefin): Efficient catalytic cross‐metathesis reactions that afford Z‐disubstituted allylic silyl or benzyl ethers are reported (see scheme, MAP=monoalkoxide pyrrolide). The approach, in combination with catalytic cross‐coupling, provides a general entry to otherwise difficult‐to‐access alkyne‐containing Z olefins.
给我一个 Z (烯烃):报告了提供Z-二取代烯丙基甲硅烷基或苄基醚的高效催化交叉复分解反应(参见方案,MAP=单烷氧基吡咯化物)。该方法与催化交叉偶联相结合,为其他难以获得的含炔烃Z 烯烃提供了通用入口。