Lewis acid promoted cyclization of enyne triesters and diesters.
Reactions of enynes with three or two ester groups (1-4) in the presence of halogen-ligand Lewis acids gave cyclized products with halide incorporation (5-8) with high generality. The cyclization process was also analyzed in a theoretical study. Facile isomerization and dehydrohalogenation of five-membered products 5 and 8 by Al(2)O(3) or Et(3)N were also observed; this process introduces conjugated moieties into the products.
Yamazaki
Shoko
S
Department of Chemistry, Nara University of Education, Japan. yamazaks@nara-edu.ac.jp
Yamada
Kuriko
K
Yamabe
Shinichi
S
Yamamoto
Kagetoshi
K