the concise total synthesis of eight natural products of the mugineic acid and avenic acid families (phytosiderophores). An innovative „east‐to‐west“ assembly of the trimeric products resulted in a high degree of divergence enabling the formation of the final products in just 10 or 11 steps each with a minimum of overall synthetic effort. Chiral pool starting materials (l‐malic acid, threonines) were
Amino acids and peptides. XXIX. A new efficient asymmetric synthesis of .ALPHA.-amino acid derivatives with recycle of a chiral reagent - asymmetric alkylation of a chiral Schiff base from glycine.
An efficient asymmetric synthesis of D-α-amino acid derivatives (VI) has been achieved by alkylation of the Schiff base (III), prepared from glycine tert-butyl ester and (1S, 2S, 5S)-2-hydroxypinan-3-one (II), followed by hydrolytic cleavage of the alkylated Schiff base (V). The chiral source (II) was also recovered in good yield, allowing the proliferation of the asymmetry according to the cycle of the amino acid asymmetric synthesis shown in Chart 1.
Synthesis of enantiomerically pure (2R, 5S)- and (2R, 5R)-5-hydroxypipecolic acid from glycinate Schiff bases
作者:Sylvie Hoarau、Jean Luc Fauchère、Louis Pappalardo、Marie Louise Roumestant、Philippe Viallefont
DOI:10.1016/0957-4166(96)00332-1
日期:1996.9
An asymmetric synthesis of cis- and trans- 5-hydroxy-(D)-pipecolic acid, starting from glycinate Schiff bases is described. The approach involves the stereoselective alkylation to generate an unsaturated side chain which on cyclisation leads to the desired trans- or cis- 5-hydroxy-(D)-pipecolic acid.