Description:
<jats:title>Abstract</jats:title><jats:p>1,3‐Functionalized cyclopentanes, ‐hexanes and ‐heptanes are obtained by addition of lithiated silyldithioacetals <jats:bold>7</jats:bold> to epoxyhomoallyl tosylates <jats:bold>4–6</jats:bold>, The reaction involves a cascade of epoxide ring opening, of Brook 1,4‐rearrangement and tosylate substitution. The method is particularly suitable for the preparation of cyclopentanes, whereas cyclohexanes and ‐heptanes are formed in yields only up to 49%. Use of enantiomerically pure epoxides provides optically active cyclopentanes (<jats:italic>S</jats:italic>)‐<jats:bold>10b, d, 11a</jats:bold> as well as oxetanes (<jats:italic>S</jats:italic>)‐<jats:bold>14a, b.</jats:bold> Hydrolysis of the dithioacetal function leads to the corresponding ketones <jats:bold>12</jats:bold>, Cyclization of epoxide <jats:bold>24b</jats:bold> gives an anellated cyclopentane <jats:bold>26</jats:bold>, the configuration of which was established by X‐ray structural analysis of dinitrobenzoate <jats:bold>27</jats:bold>. Use of epoxide <jats:bold>29b</jats:bold> provides the anellated tetrahydrofuran <jats:bold>30</jats:bold>.</jats:p>