89861-55-2Relevant academic research and scientific papers
2,3-cis-Cyclization of 4-pentenoxyl radicals
Kempter, Irina,Schur, Christine,Huttenlochner, Katharina,Bergstr??er, Ruth-Maria,Wolff, Benjamin,Kopf, Thomas,Hartung, Jens
, p. 7699 - 7714 (2016/11/13)
4-Pentenoxyl radicals cyclize 2,3-cis-selectively, when substituted by an allylic hydroxy, acetyloxy, or benzoyloxy group. Additional substituents increase or decrease the fraction of 2,3-cis-cyclized product, depending on relative configuration, position
Synthesis of enantiopure (2R)-configured muscarine alkaloids via selective alkoxyl radical ring-closure reactions
Hartung, Jens,Kneuer, Rainer
, p. 3019 - 3031 (2007/10/03)
A new synthesis of (-)-muscarine, (+)-allo-muscarine, (-)-epi-muscarine, and (-)-epiallo-muscarine has been devised which utilizes selective alkoxyl radical cyclizations for constructing tri-substituted tetrahydrofuran units. Photolysis of (2R,3S)-N-(3-benzoyloxy-5-hexen-2-oxy)-4-methylthiazole-2(3H) thione in the presence of BrCCl3 provided (2R,3S,5S)-3-benzoyloxy-5- bromomethyl-2-methyltetrahydrofuran as the major product and the corresponding (2R,3S,5R)-isomer as the minor. These building blocks were converted into enantiomerically pure (+)-allo-muscarine (from the major alkoxyl radical cyclization product) and (-)-muscarine (from the minor product). Temperature and substituent effects on the diastereoselectivity of the underlying alkoxyl radical cyclization have been investigated. (-)-epi-Muscarine and (-)-epiallo-muscarine have been prepared likewise, starting from (2R,3R)-N-(3-benzoyloxy-5-hexen-2-oxy)-4-methylthiazole-2(3H)thione.
The Invention of New Radical Chain Reactions. Part 9. Further Radical Chemistry of Thiohydroxamic Esters; Formation of Carbon-Carbon Bonds
Barton, Derek H.R.,Crich, David,Kretzschmar, Gerhard
, p. 39 - 54 (2007/10/02)
Carbon radicals derived from the esters of several types of thiohydroxamic acids have been trapped in a number of different ways.Particular attention has been paid to carbon-carbon bond formation by addition to suitably activated ethylenic linkages.Carboxylic acids can be conveniently converted into homo- and bishomo-acids by free radical chemistry based on thiohydroxamic esters.In a coda the tautomerism of the thiohydroxamic acids have been examined by physical methods.It is confirmed that the esters used are derivatives of the thione tautomer.
RADICAL CHEMISTRY OF THIOHYDROXAMIC ACID ESTERS
Barton, Derek H. R.,Kretzschmar, Gerhard
, p. 5889 - 5892 (2007/10/02)
Thiohydroxamic esters in general decompose smoothly by a radical chain reaction to give carbon radicals which can be quenched in a synthetically useful manner.
