General Access to Concave-Substituted <i>cis</i>-Dioxabicyclo[3.3.0]octanones: Enantioselective Total Syntheses of Macfarlandin C and Dendrillolide A
作者:Tyler K. Allred、André P. Dieskau、Peng Zhao、Gregory L. Lackner、Larry E. Overman
DOI:10.1021/acs.joc.0c02273
日期:2020.12.4
involves late-stage fragment coupling of a tertiary-carbon radical and an electron-deficient double bond to form vicinal quaternary and tertiary stereocenters with high fidelity. A stereoselective Mukaiyama hydration is the key step in the subsequent elaboration of the cis-2,8-dioxabicyclo[3.3.0]octan-3-one moiety. This strategy was utilized in enantioselective totalsyntheses of (−)-macfarlandin C and
Catalytic kinetic resolution of 5-alkoxy-2(5H)-furanones
作者:Wijnand S. Faber、Johan Kok、Ben de Lange、Ben L. Feringa
DOI:10.1016/s0040-4020(01)85016-x
日期:1994.4
catalysts for the kineticresolution, with quinine and quinidine leading to the most efficient and selective thiol additions. A remarkable dilution effect and a strong dependency on the mode of addition of reactants were observed. Optimization studies are presented of the kineticresolution of 5-methoxy-2(5H)-furanone 2 resulting in (R)-2 or (S)-2 with enantiomeric excesses exceeding 90%. A mechanism for the
Palladium catalyzed stereospecific allylic substitution of 5-acetoxy-2(5H)-furanone and 6-acetoxy-2H-pyran-3(6H)-one by alcohols
作者:Hanneke van der Deen、Arjan van Oeveren、Richard M. Kellogg、Ben L. Feringa
DOI:10.1016/s0040-4039(98)02683-5
日期:1999.2
Enantiomerically pure 5-acetoxy-2(5H)-furanone and 6-acetoxy-2H-pyran-3(6H)-one are converted into 5-alkoxy-2(5H)-furanones and 6-alkoxy-2H-pyran-3(6H)-ones by a palladium catalyzed allylic substitution. The reactions proceed with nearly complete retention of configuration, resulting in products with ee's of 95%.
Diastereoselective Coupling of Chiral Acetonide Trisubstituted Radicals with Alkenes
作者:Daniel J. Tao、Mikko Muuronen、Yuriy Slutskyy、Alexander Le、Filipp Furche、Larry E. Overman
DOI:10.1002/chem.201601957
日期:2016.6.20
The stereochemical outcome of reactions of chiral nucleophilic trisubstituted acetonide radicals with electron‐deficient alkenes is dictated by a delicate balance between destabilizing non‐bonding interactions and stabilizing hydrogen‐bonding between substituents on the α and β carbons.
The first totalsynthesis of a chromodorolide diterpenoid is described. The synthesis features a bimolecular radical addition/cyclization/fragmentation cascade that unites butenolide and trans-hydrindane fragments while fashioning two C-C bonds and stereoselectively forming three of the ten contiguous stereocenters of chromodorolide B.
描述了 chromodorolide 二萜的首次全合成。该合成采用双分子自由基加成/环化/断裂级联反应,将丁烯内酯和反式氢化茚片段结合在一起,同时形成两个 CC 键并立体选择性地形成 chromodorolide B 的十个连续立体中心中的三个。