14228-16-1Relevant articles and documents
Diastereoselective synthesis of cis-4-hydroxypipecolic acid from D-glucosamine
Nin, Alejandro P.,Varela, Oscar,De Lederkremer, Rosa M.
, p. 9459 - 9464 (1993)
An expeditious synthesis of cis-4-hydroxypipecolic acid (1) is described. The key step was diastereoselective hydrogenation of 2-acetamido-6-O-acetyl-2,3,5-trideoxy-hex-2-enono-1,4-lactone (3), obtained in three high yielding steps from D-glucosamine. The
2-Keto-3-Deoxy-l-Rhamnonate Aldolase (YfaU) as Catalyst in Aldol Additions of Pyruvate to Amino Aldehyde Derivatives
Hernández, Karel,Gómez, Ariadna,Joglar, Jesús,Bujons, Jordi,Parella, Teodor,Clapés, Pere
, p. 2090 - 2100 (2017)
4-Hydroxy-2-keto acid derivatives are versatile building blocks for the synthesis of amino acids, hydroxy carboxylic acids and chiral aldehydes. Pyruvate aldolases are privileged catalysts for a straightforward access to this class of keto acid compounds. In this work, a Class II pyruvate aldolase from Escherichia coli K-12, 2-keto-3-deoxy-l-rhamnonate aldolase (YfaU), was evaluated for the synthesis of amino acid derivatives of proline, pipecolic acid, and pyrrolizidine-3-carboxylic acid. The aldol addition of pyruvate to N-protected amino aldehydes was the key enzymatic aldol addition step followed by catalytic intramolecular reductive amination. The corresponding N-Cbz-amino-4-hydroxy-2-keto acid (Cbz=benzyloxycarbonyl) precursors were obtained in 51–95% isolated yields and enantioselectivity ratios from 26:74 to 95:5, with chiral α-substituted N-Cbz-amino aldehydes. (S)-N-Cbz-amino aldehydes gave aldol adducts with preferentially (R)-configuration at the newly formed stereocenter, whereas the contrary is true for (R)-N-Cbz-amino aldehydes. Addition reactions to achiral amino aldehydes rendered racemic aldol adducts. Molecular models of the pre-reaction ternary complexes YfaU-pyruvate enolate-acceptor aldehyde were constructed to explain the observed stereochemical outcome of the reactions. Catalytic reductive amination of the aldol adducts yielded 4-hydroxy-2-pipecolic acid, and unprecedented C-5 substituted 4-hydroxyproline and pyrrolizidine-3-carboxylic acid derivatives. (Figure presented.).
A concise and diastereoselective synthesis of piperidine and indolizidine alkaloids via aza-Prins cyclization
Reddy, Basi V. Subba,Chaya, Dudhmal N.,Yadav, Jhillu S.,Gree, Rene
experimental part, p. 297 - 303 (2012/03/26)
The synthesis of 2-substituted and 2,4-disubstituted piperidine alkaloids such as (±)-coniine, (±)-hydroxypipecolic acid, (±)-pipecolic acid, (±)-coniceine, and (±)-4-hydroxy-2- hydroxy-methyl piperidine have been accomplished in a highly diastereo-selective manner by employing aza-Prins cyclization as a key step to construct the piperidine core of these alkaloids. Georg Thieme Verlag Stuttgart · New York.
Chemoenzymatic synthesis of the four diastereoisomers of 4-hydroxypipecolic acid from N-acetyl-(R,S)-allylglycine: Chiral scaffolds for drug discovery
Lloyd, Richard C.,Smith, Mark E. B.,Brick, Dean,Taylor, Stephen J. C.,Chaplin, David A.,McCague, Raymond
, p. 762 - 766 (2013/09/06)
All four diastereoisomers of 4-hydroxypipecolic acid were prepared in a form conveniently protected for drug discovery applications with the use of industrially scaleable methodology. Resolution of the racemic starting material using proprietary acylases followed by an acyliminium ion cyclisation gave diastereomeric mixtures of 4-formyloxypipecolic acid, which were differentiated using an enzyme-catalysed hydrolysis. The products were separated by partition, and by following a sequence of straightforward chemical steps, the individual stereoisomers of the protected 4-hydroxypipecolates were crystallized to optical purity in 100 g quantities.
