A Convenient Reagent for the Intermolecular Coupling of Aldehydes and Ketones to Form Olefins

Abstract

When aldehydes or ketones are treated with titanium tetrachloride and amalgamated magnesium turnings in tetrahydrofuran at 0° for 2 h and subsequently under reflux for 24 h, reductive coupling occurs to give olefin in high yield. The optimum ratio of carbonyl substrate to titanium reagent was found to be 1 : 4. Examples of symmetrical and mixed couplings are given. Intramolecular coupling was not successful.