Catalytic,Enantioselective Synthesis of 1,2‐anti‐Diols by Asymmetric Ring‐Opening/Cross‐Metathesis

An enantioselective method for the synthesis of 1,2‐anti‐diols has been developed. A cyclometalated chiral‐at‐ruthenium complex catalyzes the asymmetric ring‐opening/cross‐metathesis of dioxygenated cyclobutenes, thus resulting in functionally rich synthetic building blocks. Syntheses of the insect pheromone (+)‐endo‐brevicomin and monosaccharide ribose demonstrate the synthetic utility of the 1,2‐anti‐diol fragments generated in the title reaction.