Synthesis of Kainoids via a Highly Stereoselective Hydroformylation of Kainic Acid

Abstract An efficient preparation of a series of secondary amines, structurally related to the kainic acid scaffold, is described. Naturally occurring (-)-α-kainic acid was hydroformylated with complete terminal selectivity and high stereoselectivity. The stereochemistry of the product was investigated through the ROESY and HETLOC spectra of the corresponding 2,4-dinitrophenyl hydrazone, showing the presence of a single diastereoisomer with rotamers related to the presence of the Boc group. The aldehyde was used as a platform to prepare amines by reductive amination in ionic liquids.