Novel intramolecular cyclization of N-acyliminium ions with allenylmethylsilane

ORGN 129

Moon Ho Chang, mhchang@kist.re.kr, Sang Hee Kim, Joo Hwan Cha, Ae Nim Pae, anpae@kist.re.kr, Hun Yeong Koh, and Yong Seo Cho. Biochemicals Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul, 130-650, South Korea
Novel intramolecular cyclization of allenylsilane on a-acyliminium was developed in the presence of Lewis acid as TMSOTf or InCl3in CH2Cl2. Five-membered ring derivatives having dimethylenepyrrolidinyl moiety were afforded in the presence of InCl3 or TMSOTf  in 10~84% yields. Six-membered ring derivatives bearing dimethylenepiperidinyl moiety were obtained in the presence of TMSOTf in very high yields.