Synthesis and Resolution of Substituted Pipecolic Acids
نویسنده
چکیده
-A new general method for the preparation of 2-alkyl-pipecolic acids has been developed. The syntheses of 2-methyl-, 2-benzyland cis-6-methylpipecolic acids are described. ( ) S and (+)R-2-methylpipecolic acids were resolved by fractional crystallization of the quinine salt of their N-carbobenzoxy derivative. Isolation of (-)S-cis-6-methylpipecolic acid required the use of 4-phenylbenzyloxycarbonyl as protecting group to achieve selective crystallization of the quinine salt. The absolute configurations of these compounds were determined by circular dichroism.
منابع مشابه
Switching the stereochemical outcome of 6-endo-trig cyclizations; synthesis of 2,6-cis-6-substituted 4-oxopipecolic acids.
A base-mediated 6-endo-trig cyclization of readily accessible enone-derived α-amino acids has been developed for the direct synthesis of novel 2,6-cis-6-substituted-4-oxo-L-pipecolic acids. A range of aliphatic and aryl side chains were tolerated by this mild procedure to give the target compounds in good overall yields. Molecular modeling of the 6-endo-trig cyclization allowed some insight as ...
متن کاملStereoselective preparation of lipidated carboxymethyl-proline/pipecolic acid derivatives via coupling of engineered crotonases with an alkylmalonyl-CoA synthetase.
The trisubstituted enolate- and C-C bond-forming capacities of engineered carboxymethylproline synthases CMPSs are coupled with the malonyl-CoA synthetase MatB to enable stereoselective preparation of 5- and 6-membered N-heterocycles functionalised with alkyl-substituted carboxymethyl side chains, starting from achiral alkyl-substituted malonic acids and L-amino acid semialdehydes. The results ...
متن کاملA one-pot, reductive amination/6-endo-trig cyclisation for the stereoselective synthesis of 6-substituted-4-oxopipecolic acids.
The first stereoselective synthesis of 2,6-trans-6-substituted-4-oxo-L-pipecolic acids using a tandem reductive amination/6-endo-trig cyclisation process is described. The sequential reduction and cyclisation mediated by sodium cyanoborohydride allowed the preparation of a series of highly functionalised 6-alkyl and 6-aryl analogues.
متن کاملSynthesis of Substituted α-Trifluoromethyl Piperidinic Derivatives.
A comprehensive survey of pathways leading to the generation of α-trifluoromethyl monocyclic piperidinic derivatives is provided (65 references). These compounds have been synthesized either from 6-membered rings e.g., pipecolic acid or lactam derivatives by introduction a trifluoromethyl group, from pyridine or pyridinone derivatives by reduction, and from 5-membered rings e.g., prolinol deriv...
متن کاملSynthesis and Primary Cytotoxic Screening of Some 3- Sulfonamide Substituted Benzamido-benzimidazolones
Several cycline dependent kinase 2 (CDK2) inhibitors with different chemical structures have been introduced. The hinge region of CDK2 (residues 81–84) contains a set of hydrogen bond donor and acceptor sites some of which must be satisfied for potent inhibitor binding. The benzimidazolone skeleton may provide such interactions. Accordingly, 3-sulfonamide substituted benzamido-benzimidazolones ...
متن کامل