Domino or tandem reactions have shown their unrivalled power in organic synthesis due to their high capability in merging several reactions into one operation. [1] Recently, incorporation of a 1,2-alkyl migration step into the domino/ tandem reactions has been found to be a powerful strategy for the rapid construction of architecturally complex molecules. [2] Meanwhile, selective synthesis of different products from the same starting material(s) by the subtle choice of the catalyst is a challenging issue and has attracted much interest by many chemists in recent years. [3][4][5] Recently, Kirsch and co-workers reported an interesting Au III -and Pt II -catalyzed tandem heterocyclization and pinacol-type rearrangement for the efficient synthesis of substituted 3A C H T U N G T R E N N U N G (2 H)-furanones, in which the oxygen lone pair of the hydroxy group may provide the critical driving force (Scheme 1). [6] Very recently, we developed a tBuOK-catalyzed tandem Michael addition of crotonate-derived malonate 1 with 2-(1-alkynyl)-2-alken-1-ones 2 that led to the formation of highly substituted, multifunctionalized cyclopentanes 3 in good yields. [7] During this study, we envisioned that compounds 3 would form an oxonium-containing vinylgold intermediate in the presence of cationic gold complex, which might in turn undergo a 1,2-alkyl migration through pathway a or b (Scheme 1) and subsequent transformations through pathway c or d. For this hypothesis, two challenging selectivity issues need to be addressed: 1) the regioselective 1,2-alkyl migration (pathway a or b), especially when R 3 is an alkyl group; 2) how to selectively get one product if several products can be formed. We report herein a cationic gold(I)-catalyzed domino reactions consisting of highly regioselective and stereospecific 1,2-alkyl migration and heterocyclization or oxygen transfer. [2k, 8] We tested this hypothesis by examining the tandem reaction of ketone 3 a under the catalysis of cationic gold(I) complex. After several attempts, pleasingly, the reaction succeeded under conditions A (Scheme 2): IPrAuCl/AgOMs (5 mol %), 1,2-dichloroethane (DCE), 80 8C gave the fused 5,6-bicyclic 6 a containing a quaternary carbon stereocenter in 94 % isolated yield as a single diastereomer. The bicyclic compound 6 a was produced by a tandem regioselective 1,2-