The rapid photomediated alkenylation of 2-alkyl-1,3-dioxolanes with alkynes: a stereoelectronically assisted chain reaction
作者:Niall W. A. Geraghty、Andrea Lally
DOI:10.1039/b608979h
日期:——
The photomediated reaction of alkynes such as DMAD with 1,3-dioxolanes leads to remarkably rapid alkenylation; evidence is presented that these reactions occur via a chain mechanism.
Acetals of γ-oxo-α,β-unsaturated esters in nitrone cycloadditions. Regio- and stereochemical implications
作者:Ramon Alibés、Félix Busquè、Pedro de March、Marta Figueredo、Josep Font、Maria Esmeralda Gambino、Brian A. Keay
DOI:10.1016/s0957-4166(01)00294-4
日期:2001.7
Several acetals of gamma -oxo-alpha,beta -unsaturated esters have been prepared, mainly from enantiopure C-2-symmetric diols, and their 1,3-dipolar cycloaddition to 2,3,4,5-tetrahydropyridine 1-oxide has been studied. All the reactions showed complete regio selectivity and a high preference for the endo approach of the reactants in the transition state. The enantiopure acetals derived from (cis, cis) -spiro [4.4]nonane- 1, 6-diol gave the highest diastereofacial selectivity. (C) 2001 Elsevier Science Ltd. All rights reserved.
Chemistry of insect antifeedants from Azadirachta indica(part 13): on the use of the intramolecular Diels–Alder reaction for the construction of trans-fused hydrobenzofuran fragments for azadirachtin synthesis
作者:Hartmuth C. Kolb、Steven V. Ley、Richard N. Sheppard、Alexandra M. Z. Slawin、Stephen C. Smith、David J. Williams、Anthony Wood
DOI:10.1039/p19920002763
日期:——
This paper describes a detailed analysis of the influence of various substituents on the stereochemical outcome of the intramolecular Diels–Alder cyclisation of a number of ether-linked trienes. In particular, the role of diene planarity in governing reaction synchronicity and related twist asynchronicity is delineated. Additionally, the controlling influence of a large dimethyl(phenyl)silyl substituent