Enantioselective synthesis of cis-(2S,3R)- and trans-(2S,3S)-piperidinedicarboxylic acids using domino: allylic acetate and Ireland-Claisen rearrangements and Michael addition as the key steps
An enantioselective synthesis of (2S,3R)-piperidine-2,3-dicarboxylic acid and (2S,3.9-piperidine-2,3-dicarboxylic acid is described. This synthesis was mainly based on a delta-amino acid formation via a domino reaction: allylic acetate rearrangement, stereoselective Ireland-Claisen rearrangement and asymmetric Michael addition protocol from a Baylis-Hillman adduct, in which the cinnamaldehyde double bond is a masked carboxylic functionality, and a cerium(IV) ammonium nitrate promoted monodebenzylation. (C) 2011 Elsevier Ltd. All rights reserved.