1.
Org Lett
; 8(24): 5509-12, 2006 Nov 23.
Article
in English
| MEDLINE
| ID: mdl-17107059
ABSTRACT
A two-step protocol for the asymmetric synthesis of protected quaternary (E)-vinylglycines from simple aldehydes is reported. The key step is a regiocontrolled deconjugative asymmetric alkylation of dehydroamino acids, giving the targets as single geometric isomers with high diastereoselectivity (92-96% de). The products can be converted to valuable quaternary beta-amino alcohols by chemoselective reduction. [reaction: see text].
Subject(s)
Amino Acids/chemistry , Glycine/analogs & derivatives , Aldehydes/chemical synthesis , Alkylation , Chromatography, High Pressure Liquid , Crystallography, X-Ray , Glycine/chemical synthesis , Magnetic Resonance Spectroscopy , Oxidation-Reduction , Stereoisomerism
2.
Org Lett
; 7(24): 5433-6, 2005 Nov 24.
Article
in English
| MEDLINE
| ID: mdl-16288524
ABSTRACT
[reaction: see text] A practical and general two-step synthesis of carbamate-protected (E)-vinylglycines from aliphatic aldehydes is reported. The key step involves the kinetic alpha-protonation of dianionic dienolates derived from dehydroamino acids.
