作者:Christine Zioudrou、Irene Moustakali-Mavridis、Polyxene Chrysochou、Gerasimos J. Karabatsos
DOI:10.1016/0040-4020(78)87014-8
日期:1978.1
The diastereomeric product ratios from reactions involving the addition of various reagents to the carbonyl of φCH3HC-COR compounds varies over a wide range. This variation is interpreted as due partly to changes in the structure of the diastereomeric transition states with changes in the size of R. For example, when R is smaller than the φCH3HC group the diastereomeric product ratios are close to
Some unusual aspect aspects of organocopper chemistry: lithium organocuprate reaction with some neopentylic p-tosylate esters
作者:Gary H. Posner、Kevin A. Babiak
DOI:10.1016/s0022-328x(00)92356-8
日期:1979.9
Diphenylcopperlithium and dimethylcopperlithium react differently with the same primary neopentylic tosylate ester. Several secondary neopentylic tosylates react with organocopperlithium reagents to give olefins via a concerted anti-1,2-dehydrosulfonation. When anti-elimination is not possible, skeletal rearrangement occurs.
About the stereoselectivity control in reactions of chiral ortho-sulfinyl benzyl carbanions with aldehydes
作者:José L Garcı́a Ruano、M.Teresa Aranda、José M Aguirre
DOI:10.1016/j.tet.2004.04.051
日期:2004.6
compounds, anti-3 and syn-4, epimers at hydroxylic carbon, easily separated by chromatography and desulfinylated into enantiomerically pure 1-alkyl (or aryl)-2-phenyl-1-propanols. The observed stereoselectivity at C(1) and C(2) is analyzed to the light of the steric and electronic effects of the substituents.
On the reduction of enol acetates and enolates derived from α-chiral ketones with lithium tetrahydridoaluminate
作者:Guillermo Orellana、Rafael Pérez-Ossorio、María L. Quiroga、María P. Sánchez-Asiaín
DOI:10.1039/p29870000679
日期:——
completely stereoselective in the (RR,SS)-alcohol. Form these results and the observation of the stereochemistry and conversion during the reaction, a mechanism is proposed. This includes a metallated ketone as a chiral intermediate in the reduction process.
The conformations of a diastereoisomericpair of 2,2-dimethyl-4-phenyl-3-pentanols were studied by means of 1H-NMR, 13C-NMR, IR, GC, and MS analyses. All of the results point to an unambiguous conclusion that these molecules are present dominantly in conformers where the t-butyl and the phenyl group lie close to each other. The generality of the phenomenon (favored gauche interaction) as well as the
通过 1H-NMR、13C-NMR、IR、GC 和 MS 分析研究了 2,2-二甲基-4-苯基-3-戊醇的非对映异构体对的构象。所有结果都指向一个明确的结论,即这些分子主要存在于叔丁基和苯基彼此靠近的构象异构体中。根据结构相关分子的构象问题讨论了该现象的一般性(有利的 gauche 相互作用)以及所涉及的相互作用的性质。烷基和苯基之间存在吸引相互作用(CH/π 相互作用),然后在此基础上讨论了在某些动态现象(例如,某些反应中的选择性)中可能的重要性。