An Efficient Method for Cyclopentene Annulation onto α,β-Unsaturated Ketones: W(CO)5(L)-Catalyzed 5-Endo-Dig Cyclization of 6-Siloxy-5-en-1-ynes

초록

(Matrix Presented) A highly efficient method for the cyclopentene annulation onto α,β-unsaturated ketones is described. Indium-mediated 1,4-propargylation onto α,β-unsaturated ketones in the presence of tert-butyldimethylsilyl triflate and dimethyl sulfide gives the 6-siloxy-5-en-1-yne derivatives, which undergo W(CO)<inf>5</inf>(L)-catalyzed 5-endo-dig cyclization to give the corresponding cyclopentene derivatives in good yield.