857294-05-4Relevant articles and documents
Synthesis of α,α-disubstituted α-amino acid derivatives in enantiopure form via stereoselective addition of Grignard reagents to a chiral acyclic nitrone derived from L-erythrulose
Portole?s, Raul,Murga, Juan,Falomir, Eva,Carda, Miguel,Uriel, Santiago,Marco, J. Alberto
, p. 711 - 714 (2002)
The additions of various Grignard reagents to a chiral nitrone prepared from L-erythrulose take place with variable diastereoselectivity. The degree and strength of the facial selectivity can be modified if the reaction is performed in the presence of Lewis acidic additives: zinc bromide enhances attack to the si face whereas diethyl aluminum chloride promotes attack to the re side. The obtained adducts can be then efficiently transformed into protected N-hydroxy α,α-disubstituted α-amino acid derivatives as well as into the corresponding α,α-disubstituted α-amino acids.
Stereoselective addition of organometallic reagents to a chiral acyclic nitrone derived from L-erythrulose
Murga, Juan,Portoles, Raul,Falomir, Eva,Carda, Miguel,Marco, J. Alberto
, p. 1807 - 1816 (2007/10/03)
The additions of various organolithium and organomagnesium reagents to a chiral nitrone prepared from L-erythrulose took place with variable diastereoselectivity. The degree and strength of the facial selectivity can be modified if the reaction is performed in the presence of Lewis acid additives: zinc bromide enhances the attack to the Si face of the C=N bond whereas diethyl aluminium chloride promotes attack to the Re face. The obtained adducts can be then transformed into protected N-hydroxy-α,α-disubstituted-α- amino acid derivatives as well as into the corresponding α,α- disubstituted α-amino acids.
