W(CO)₅(L)-Catalyzed Tandem Intramolecular Cyclopropanation/Cope Rearrangement for the Stereoselective Construction of Bicyclo[5.3.0]decane Framework

Utilizing the biscarbene character of electrophilically activated alkynes, a novel tandem intramolecular cyclopropanation/Cope rearrangement of 3-siloxy-1,3,9-trien-7-ynes catalyzed by W(CO)₅(L) for the stereoselective construction of bicyclo[5.3.0]decane framework is achieved. When 3-siloxy-1,3,9-trien-7-ynes were treated with a catalytic amount of W(CO)₆ under photoirradiation, bicyclo[5.3.0]decanes were obtained in good yield stereoselectively. In this reaction, the Cope rearrangement of the divinylcyclopropane intermediates, generated by the intramolecular cyclopropanation of 3-siloxy-1,3,9-trien-7-ynes based on the W(CO)₅(L)-catalyzed electrophilic activation of alkynes, occurs to give synthetically useful functionalized bicyclo[5.3.0]decane derivatives stereoselectively.