ISSN:
0947-3440
Schlagwort(e):
Electron transfer reactions
;
Radical additions
;
1,3-Asymmetric induction
;
Alkenes
;
γ-Lactones
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Alkyl 2-iodoalkanoates 2, and 2-iodoalkanenitriles 15 were added, with copper powder, to the 1-alkenes 1a, e, f, and h, and to the alkenes 1b, c, d, and g with a 1,2-dialkyl substituted double bond, to give, respectively, γ-lactones and 4-iodoalkanenitriles in very good yields. No solvent was used. The reaction is a free radical addition initiated by electron transfer from copper to the activated iodoalkane. Yields were lower using the respective bromo compounds. In situ formation of the iodo compounds, by addition of stoichiometric amounts of sodium iodide to the reaction mixture, gave improved yields. In the case of the methyl bromomalonates 6, the addition of sodium iodide proved to be unnecessary. The diastereoselectivity of the addition reaction by relative 1,3-asymmetric induction was rationalized by consideration of the steric interactions of the substituents in the transition state which is formed in the process of iodine transfer to the chiral adduct radical.
Zusätzliches Material:
4 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jlac.199719971119
Permalink
