Conia-ene annulation of the α-cyano ß-TMS-capped alkynyl cycloalkanone system and its synthetic application.

Under catalysis with ZnI(2), an effective annulation process of ω-silylacetylenic α-cyano ketones, leading to the formation of various bicyclic frameworks characterized with a TMS-containing methylenecyclopentane ring, has been developed.