Abstract A new approach is demonstrated for the synthesis of macrotetralides through an olefin metathesis reaction using Grubbs' second-generation catalyst with titanium isopropoxide as a cocatalyst. This study demonstrates a tandem self-cross and ring-closing metathesis approach to form macrocyclic ring systems with excellent (E) selectivity. The reaction was optimized with regard to functional group, catalyst, solvent, Lewis acid, ...