The in situ generation of alk-1-ynyllead triacetates from terminal acetylenes by zinc–lead exchange and crystal structure of 2,4,7,9,13-pentamethyl-9-phenylethynyl-7,10-ethenospiro[5.5]undeca-1,4- diene-3,8-dione

Abstract

Methods involving zinc–lead exchange for the one-pot conversion of terminal acetylenes into alk-1-ynyllead(IV) triacetates have been developed, and examples of the in situ C-alkynylation of a number of carbon nucleophiles are reported. An attempt to extend the reaction to phenols by treating 2,4,6-trimethylphenol with phenylethynyllead triacetate led to formation of the spiro dienone 16, the structure of which was determined by X-ray diffraction.