Six- versus five-membered ring formation in radical cyclizations of 7-bromo-substituted hexahydroindolinones.
[reaction: see text] Radical cyclization of N-allyl-7-bromo-3a-methyl-hexahydroindol-2-one affords a six-membered ring product that prevails over the isomeric five-membered compound. The former product is generated through two reaction pathways: (a) 6-endo-trig ring closure and (b) rearrangement of an intermediate methylenecyclopentyl radical obtained by 5-exo-trig cyclization.
Rashatasakhon
Paitoon
P
Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
Ozdemir
Ayse Daut
AD
Willis
Jerremey
J
Padwa
Albert
A