ISSN:
0947-3440
Keywords:
β-Amino acids
;
Michael addition
;
Chiral ammonia equivalent
;
TMS-SAMP
;
MIRC reaction
;
Asymmetric synthesis
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The stereoselective conjugate addition of (S)-(-)-1-(trimethylsilylamino)-2-(methoxymethyl)pyrrolidine (TMS-SAMP) to ω-halide-substituted α,β-unsaturated esters 1 is utilized to prepare carbocyclic and heterocyclic β-amino acids 2 and 5 of high diastereo- and enantiomeric purity via the corresponding β-hydrazino esters by selective intramolecular alkylation of the intermediate ester enolate or the hydrazino moiety. The auxiliary is removed by reductive N—N bond cleavage. The stereochemistry of the resulting trans-2-aminocycloalkanecarboxylic acids (2) and azacycloalk-2-ylacetic acid esters (5) is confirmed by NMR spectroscopy and polarimetry. A transition-state model for the highly diastereoselective conjugate addition of TMS-SAMP to enoates is presented.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199719970410
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