Determination of the absolute stereochemistry and asymmetric total synthesis of madindolines A and B: a practical improvement to a second-generation approach from the first-generation
In this report, we describe an efficient, highly convergent, stereocontrolled first totalsynthesis and a second-generation synthesis of madindolines A 1 and B 2, potent selective inhibitors of interleukin 6. The key steps include (1) asymmetric oxidative ring-closure reaction of tryptophol 3 to construct a chiral 3a-hydroxyfuroindoline 4 using the modified Sharpless asymmetric epoxidation condition
Atom Economy in the Metathesis Cross-Coupling of Alkenes and Alkynes
作者:Joseph R. Clark、Steven T. Diver
DOI:10.1021/ol200914j
日期:2011.6.3
A cross ene-yne metathesis has been achieved at a nearly 1:1 stoichiometry of the unsaturated reactants. This allowed the use of more complex alkene reactants without sacrificing excess alkene reactant. In the alkene, different allylic oxygen protecting groups were explored. Interestingly, alkenes containing the allylic hydroxyl group proved to be the most reactive.
Syn-and anti-methyl 2-substituted 3-hydroxy-4-pentenoates were efficiently resolved in lipase-catalyzed transesterification. This protocol was successfully applied to the synthesis of the taxol side chain.
Iodocyclization of allylic alcohol derivatives containing internal nucleophiles. Control of stereoselectivity by substituents in the acyclic precursors
作者:A. Richard Chamberlin、Milana Dezube、Patrick Dussault、Mark C. McMills
DOI:10.1021/ja00356a020
日期:1983.9
La reaction d'acides hydroxy-3 alcene-4oiques avec l'iode en milieu biphasique neutre donne une cyclisation stereoselective habituellement en cis-hydroxy-3 iodo-4 lactone. Effet des substituants
La 反应 d'acides hydroxy-3 alcene-4oiques avec l'iode en milieu biphasique neutre donne une 环化立体选择性习惯 en cis-hydroxy-3 iodo-4 内酯。替代物的作用
Synthesis of Optically Active α-Methyl β-Hydroperoxy Esters by Diastereoselective Singlet Oxygen Ene Reaction and Horseradish Peroxidase Catalyzed Kinetic Resolution
作者:Waldemar Adam、Chantu R. Saha-Möller、Oliver Weichold
DOI:10.1007/s007060070098
日期:2000.6.15
Optically active diastereomeric β-hydroperoxy esters 4 have been prepared by singletoxygenenereaction of β,γ-unsaturated esters 3 and subsequent horseradish peroxidase (HRP) catalyzed kinetic resolution of the eneproduct. The highest enantiomeric excess (up to 95%) has been obtained for the isopropyl ester threo - 4c , which establishes that the size of the remote ester functionality exercises