Mechanistic aspects of thiyl radical-promoted acyl radical cyclization of formylenoate-cyclization versus oxidation.
Treatment of formylalkenoates 1 and 7 with 2,2'-azobis(2-methylpropanenitrile) (AIBN) in the presence of dioxygen gave oxygenated carboxylic acids 5, 6, 8, 9 instead of acyl radical cyclization products, through preferential reaction of the corresponding acyl radicals with dioxygen rather than intramolecular attack to an enoate moiety. The reaction of 1 with AIBN in the absence of dioxygen recovered starting 1 in 98% yield.
Yoshikai
Kazuya
K
Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Kyoto 606-8501, Japan.
Hayama
Tomoharu
T
Nishimura
Katsumi
K
Yamada
Ken-ichi
K
Tomioka
Kiyoshi
K
D003500:Cyclization; D005609:Free Radicals / Q000737:chemistry* / Q000378:metabolism*; D010084:Oxidation-Reduction
D005609:Free Radicals