Intramolecular Hydrogen Abstraction Reaction Promoted by Alkoxy Radicals in Carbohydrates. Synthesis of Chiral 2,7-Dioxabicyclo[2.2.1]heptane and 6,8-Dioxabicyclo[3.2.1]octane Ring Systems
作者:Cosme G. Francisco、Antonio J. Herrera、Ernesto Suárez
DOI:10.1021/jo026004z
日期:2002.10.1
for the synthesis of chiral 6,8-dioxabicyclo[3.2.1]octane and 2,7-dioxabicyclo[2.2.1]heptane ring systems under neutral conditions. This reaction can be considered to be an intramolecular glycosidation that goes through an intramolecular hydrogen abstraction promoted by an alkoxy radical followed by oxidation of the transient C-radical intermediate to an oxycarbenium ion. This methodology is useful
Intramolecular Hydrogen Abstraction Reaction Promoted by <i>N</i>-Radicals in Carbohydrates. Synthesis of Chiral 7-Oxa-2-azabicyclo[2.2.1]heptane and 8-Oxa-6-azabicyclo[3.2.1]octane Ring Systems
作者:Cosme G. Francisco、Antonio J. Herrera、Ernesto Suárez
DOI:10.1021/jo026314h
日期:2003.2.1
The reaction of phenyl and benzyl amidophosphates and alkyl and benzyl carbamate derivatives of aminoalditols with (diacetoxyiodo)benzene or iodosylbenzene and iodine is a mild and selective procedure for the synthesis of chiral 7-oxa-2-azabicyclo[2.2.1]heptane and 8-oxa-6-azabicyclo[3.2.1]octane ring systems under neutral conditions. This reaction can be considered to be an intramolecular N-glycosidation
Free‐Radical Epimerization of
<scp>d</scp>
‐ into
<scp>l</scp>
‐
<i>C</i>
‐(Glycosyl)methanol Compounds Using 1,5‐Hydrogen Atom Transfer Reaction
作者:Adrián S. Montes、Elisa I. León、Ángeles Martín、Inés Pérez‐Martín、Ernesto Suárez
DOI:10.1002/ejoc.202101391
日期:2022.4.27
C5 of readily accessible d- or l-carbohydrates, by means of a remote reductive radical sequence was described. A comparative study of the radical process promoted by a tin reagent or with photoredox conditions was also performed. The stereochemical and polarity influence of the substituents in the course of the radical sequence was considered.
描述了通过远程还原自由基序列在容易获得的d-或l-碳水化合物的 C5 处进行长程差向异构化制备对映异构纯的顺式- C - 糖基化合物。还进行了由锡试剂或光氧化还原条件促进的自由基过程的比较研究。考虑了取代基在自由基序列过程中的立体化学和极性影响。