A concise diastereotioselective strategy for the synthesis of noscapine, bicuculline, and egenine (1a–c), as well as capnoidine and corytensine (2a, b), was developed using diastereoselective addition of 1-siloxy-isobenzofurans 4a and 4b to iminium ion 5 in a one- pot approach. The synthesis features the use of imine 13 obtained through Bischler– Napieralsky reaction from amine 11. The addition of ionic liquids as addictives in the ...