Exner, Claudia J.Turks, MarisFonquerne, FreddyVogel, Pierre2011-12-162011-12-162011-12-16201110.1002/chem.201003264https://infoscience.epfl.ch/handle/20.500.14299/74153WOS:000290101500024Herein, a major breakthrough in a sulfur dioxide-mediated oxyallylation cascade reaction is reported that allows the preparation of complex long-chain polyketide fragments with more than ten stereogenic centers through a carefully designed desymmetrization process. An allylbissilane is combined, under the appropriate reaction conditions, with two different 1,3-dioxy-1,3-dienes permitting the construction of a 13-membered polypropionate precursor in one pot. Four stereocenters are selectively created during this process. The so-obtained pseudo-C-2- or -C-S-symmetric products are desymmetrized through selective deprotection and can be selectively elongated in both directions using aldol chemistry.aldol reactionallylsilanesasymmetric synthesispolyketidessulfur dioxidetandem reactionsDiels-Alder AdditionAsymmetric-SynthesisSulfur-DioxideAbsolute-ConfigurationPolyketide SynthesisDirected ReductionBuilding-BlocksAssignmentFragmentsAllylsilanestext::journal::journal article::research article