title: Diastereoselective synthesis of quaternary alpha-amino acids from diketopiperazine templates.
abstract: Sequential enolate alkylations of (S)-N(1)-methyl-5-methoxy-6-isopropyl-3,6-dihydropyrazin-2-one and (S)-N(1)-p-methoxybenzyl-5-methoxy-6-isopropyl-3,6-dihydropyrazin-2-one proceed with excellent levels of diastereoselectivity (>90% de) affording quaternary alpha-amino acids in high enantiomeric excess (>98% ee) after deprotection and hydrolysis.
authors.affiliation: Department of Organic Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK. steve.davies@chem.ox.ac.uk
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Davies
authors.forename: A Christopher
authors.initials: AC
authors.lastname: Garner
authors.forename: Jaqueline V A
authors.initials: JV
authors.lastname: Ouzman
authors.forename: Paul M
authors.initials: PM
authors.lastname: Roberts
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Smith
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Snow
authors.forename: James E
authors.initials: JE
authors.lastname: Thomson
authors.forename: Juan A
authors.initials: JA
authors.lastname: Tamayo
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Vickers
mesh_terms: D000478:Alkylation; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D054659:Diketopiperazines; D006868:Hydrolysis; D007769:Lactams / Q000737:chemistry; D008745:Methylation; D008958:Models, Molecular; D015394:Molecular Structure; D010879:Piperazines / Q000737:chemistry*; D011522:Protons; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D054659:Diketopiperazines; D007769:Lactams; D010879:Piperazines; D011522:Protons