Domino reactions facilitate the rapid assembly of complex products in a one-pot process. [1] Despite the simplicity of the idea, domino cyclizations of 1,3-dicarbonyl dianions [2] with dielectrophiles are relatively rare. [3] As a result of their high negative charge density, ambident dianions are very reactive compounds, and many side reactions can occur, such as polymerization, decomposition, deprotonation, formation of open-chain products, elimination, and single-electron-transfer processes. A number of base-mediated cyclization reactions of activated (symmetrical) 1,3,5-tricarbonyl compounds (e.g. diethyl acetone-1,3-dicarboxylate) with enolizable 1,3-dicarbonyl derivatives have been reported. [4] In contrast, many side reactions, such as deprotonation or reduction of the dielectrophile, can interfere with the direct cyclization of (unsymmetrical) 1,3-dicarbonyl dianions with enolizable and nonenolizable 1,3-diketones. [5] A solution to this problem was developed by Chan and co-workers. They reported the synthesis of benzene derivatives and salicylic acid esters by the Lewis acid mediated cyclization of acetals of b,bketoaldehydes, b-ketocarboxylic acid esters, and b-ketocarboxylic acid chlorides (Scheme 1 a), and of 3-silyloxyalk-2-en-1-ones (Scheme 1 b) with 1,3-bis(silyl enol ether)s. 1,3-Bis-Scheme 1. Cyclizations of 1,3-bis(silyl enol ether)s reported by Chan et al. [6b, 8] [