Highly Efficient Synthesis of cis-[3]Cumulenic Diols via Zirconocene-Mediated Coupling of 1,3-Butadiynes with Aldehydes

A highly efficient and convenient method for the monozirconation of silyl- or tert-butyl-substituted 1,3-butadiynes using the Negishi reagent has been developed. The resulting zirconium butadiyne complexes undergo two syn-S(E)2' reactions with various aldehydes to yield the cis-[3]cumulenic diols with moderate to high diastereoselectivities. The silyl substituents at the butadiyne terminus show remarkable influence on the diastereoselectivity.