title: Synthesis of C-protected alpha-amino aldehydes of high enantiomeric excess from highly epimerizable N-protected alpha-amino aldehydes.
abstract: A new procedure for the preparation of C-protected alpha-amino aldehydes of high enantiomeric excess is illustrated using five differently substituted alpha-(N-Fmoc)amino aldehydes as starting materials. Highly epimerization-prone substrates were converted to the corresponding morpholino nitrile-protected alpha-amino aldehydes with minimal racemization (products >/= 89% ee). Morpholino nitrile derivatives of phenylglycinal were crystallized and subjected to X-ray structural analysis, allowing for definitive determination of the stereochemistry of amino nitrile formation. A rationale for the stereoselectivity of amino nitrile formation is presented.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA. myers@chemistry.harvard.edu
authors.forename: A G
authors.initials: AG
authors.lastname: Myers
authors.forename: B
authors.initials: B
authors.lastname: Zhong
authors.forename: D W
authors.initials: DW
authors.lastname: Kung
authors.forename: M
authors.initials: M
authors.lastname: Movassaghi
authors.forename: B A
authors.initials: BA
authors.lastname: Lanman
authors.forename: S
authors.initials: S
authors.lastname: Kwon
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism; D014961:X-Ray Diffraction
chemical_list: D000447:Aldehydes