Gold catalyzed spirocyclization of 1-ene-4,9- and 3-ene-1,7-diyne esters to azaspiro[4.4]nonenones and azaspiro[4.5]decadienones

A method to prepare a structurally diverse range of spirocyclic cyclopentanes, furans, pyrrolidines and piperidines, which relies on the gold( i )-catalyzed spirocyclization of 1-ene-4,9- and 3-ene-1,7-diyne esters, has been developed.