Control of up to five stereocenters in a cascade reaction: Synthesis of highly functionalized five-membered rings

Mukaiyama-Aldol and Prins reactions have been identified as highly efficient methods in C-C bond formation since they were discovered several decades ago. Since both reactions gave the same common intermediate, oxocarbonium, we intend to combine the two reactions into a domino process, which means the formation of multiple C-C bonds and stereogenic centers in one pot without isolation of any intermediates. We envisage that the domino reactions involving the Mukaiyama-Aldol reaction of silyl enol ether and acetal treated with Lewis acid (TiBr₄) will produce an oxonium intermediate which upon trapping by an alkene functionality in an intramolecular Prins cyclization will generate the cyclopentyl ring system.