Intramolecular Allylsilane Addition to Chiral Alkylidene‐1,3‐dicarbonyl Compounds for the Synthesis of Enantiomerically Pure trans‐1,2‐Disubstituted Cyclopentanes and Cyclohexanes

Three new stereogenic centers characterize the 1,2-trans-disubstituted cyclopentanes 2a and cyclohexanes 2b, which can be prepared enantiomerically pure with the Lewis acid SnCl4 in a highly selective SnCl4-induced cyclization of the chiral alkylidene malonic acid derivatives 1a and 1b, respectively. The chiral auxiliary can be removed from 2 with LiAlH4.