Siloxycyclopropanes in Ugi Four-Component Reaction: A New Method for the Synthesis of Highly Substituted Pyrrolidinone Derivatives - Zimmer, Reinhold; Ziemer, Antje; Gruner, Margit; Brüdgam, Irene; Hartl, Hans; Reissig, Hans-Ulrich (Synthesis, 2001)