Is pseudorotation the operational pathway for bond shifting within [8]annulenes? Probe of planarization requirements by 1,3-annulation of the cyclooctatetraene ring. Kinetic analysis of racemization and 2-D NMR quantitation of .pi.-bond alternation and ring inversion as a function of polymethylene chain length
Iodine(V) Reagents in Organic Synthesis. Part 4. <i>o</i>-Iodoxybenzoic Acid as a Chemospecific Tool for Single Electron Transfer-Based Oxidation Processes
作者:K. C. Nicolaou、T. Montagnon、P. S. Baran、Y.-L. Zhong
DOI:10.1021/ja012127+
日期:2002.3.1
o-Iodoxybenzoic acid (IBX), a readily available hypervalent iodine(V) reagent, was found to be highly effective in carrying out oxidations adjacent to carbonyl functionalities (to form alpha,beta-unsaturated carbonyl compounds) and at benzylic and related carbon centers (to form conjugated aromatic carbonyl systems). Mechanistic investigations led to the conclusion that these new reactions are initiated
Regio- and stereospecific [3+2] cycloaddition of an unusual nitrone derived from a N-hydroxy-2-pyridone with medium ring enones
作者:Nageswara Rao Irlapati、Jack E. Baldwin、Robert M. Adlington、Gareth J. Pritchard、Andrew R. Cowley
DOI:10.1016/j.tet.2004.12.019
日期:2005.2
stereospecific 1,3-dipolar cycloaddition of the nitrone derived from a N-hydroxy-2-pyridone 6 with Z-2-cyclodecenone 7a was accomplished, thus substantiating a possible biomimetic route to pyridomacrolidin 2 from pyridovericin 1 and cephalosporolide B 5. This reaction was further exemplified with different enones (7a–g) similar to cephalosporolide B 5. In all the cases the cycloaddition occurred with high
Preparation of cis- and trans-cyclodec-2- and -3-enones and studies of interconversions between them
作者:G. H. Whitham、M. Zaidlewicz
DOI:10.1039/p19720001509
日期:——
The cis- and trans-cyclodec-2- and -3-enones have been synthesised by stereospecific routes; a preparation of 3-hydroxycyclodecanone has also been developed. Under conditions of acid catalysis cis- and trans-cyclodec-2-enones are rapidly interconverted to give an equilibrium mixture containing 96% of the cis- and 4% of the trans-isomer. Efficient equilibration with the unconjugated isomers was not
An Unusual Oxidative Cyclization: Studies towards the Biomimetic Synthesis of Pyridomacrolidin
作者:Nageswara Rao Irlapati、Jack E. Baldwin、Robert M. Adlington、Gareth J. Pritchard、Andrew Cowley
DOI:10.1021/ol034736n
日期:2003.6.1
An unusual oxidative cyclization of a N-hydroxy pyridone 9 with Z-2-cyclodecenone 11 has been achieved, thus demonstrating a possible biomimetic route to pyridomacrolidin 2. [reaction: see text]
Studies towards the biomimetic synthesis of pyridomacrolidin
作者:Nageswara Rao Irlapati、Jack E. Baldwin、Robert M. Adlington、Gareth J. Pritchard、Andrew R. Cowley
DOI:10.1016/j.tet.2006.01.090
日期:2006.5
A possible biomimetic synthesis of pyridomacrolidin has been proposed and experimentally supported by carrying out a modelstudy. Regio and stereospecific [3+2] cycloaddition of an in situ generated unusual di-tert-butylated acyl nitrone with Z-2-cyclodecenone and subsequent aromatisation was the key step in our proposed biomimetic synthesis. Finally a pyridomacrolidin analogue was prepared via Friedel–Crafts