Gold-Catalyzed Tandem C−C and C−O Bond Formation: A Highly Diastereoselective Formation of Cyclohex-4-ene-1,2-diol Derivatives

We have reported an efficient gold(I)-catalyzed tandem cyclization of tert-butyl carbonate derivatives of hex-1-en-5-yn-3-ol where nucleophilic participation of the O-Boc group appears to intercept a carbocationic (or cyclopropyl carbene) Au intermediate. This novel protocol leads to densely functionalized cyclohexene-3,4-diol derivatives where 1,2- or 1,2,3-stereocenters are controlled in a highly diastereoselective fashion.