Cascade reactions with chiral michael acceptors; synthesis of enantiomerically pure tricyclo[3.2.1.0^2,7]‐ and bicyclo[3.2.1]octanes

Abstract

Abstract Starting from the easily accesible chiral aldehyde 2 , we obtained enantiomerically pure ( Z )‐ and ( E )‐α,‐chloro‐α,β‐unsaturated esters 4c in good yields by olefination reactions. ( Z )‐and ( E )‐ 4c were allowed to react with the kinetically controlled generated lithium dienolate Li‐ 7 to give the enantiomerically pure tricyclo[3.2.1.0 2,7 ]octanes 8 and 9 , respectively. The „push‐pull”︁ substituted cyclopropane moiety of 8 was opened to give solely bicyclo[3.2.1]octane 10 .