Proton abstraction and electrophilic quench at C-2 of imidazolidines
摘要:
Imidazolidines bearing tert-butoxycarbonyl groups on both nitrogen atoms have been prepared in order to test their ability to act as acyl anion equivalents. Proton abstraction was achieved successfully at C-2, between the two nitrogen atoms, using the base sec-butyllithium. The resulting organolithium was trapped with a variety of electrophiles. The imidazolidine can be cleaved with acid to generate the desired carbonyl compound. Using chiral imidazolidines and aldehyde electrophiles, the carbon-carbon bond formation occurred with low diastereoselectivities. (C) 1998 Elsevier Science Ltd. All rights reserved.