Highly diastereoselective addition of nitromethane anion to chiral alpha-amidoalkylphenyl sulfones. Synthesis of optically active alpha-amino acid derivatives.
Optically active syn-alpha-amidoalkylphenyl sulfones can be prepared from chiral aldehydes in anhydrous conditions using benzenesulfinic acid. These sulfones in basic conditions give N-acylimines that react with sodium methanenitronate to afford the corresponding nitro adducts with high anti diastereoselectivity. PM3 semiempirical calculations provide a rationale for the observed opposite stereoselectivity. The obtained nitro derivatives undergo a Nef reaction followed by a methylation giving optically active beta-hydroxy-alpha-amino acid and alpha,beta-diamino acid esters in good yield. These amino acid derivatives are important building blocks for the preparation of biologically active compounds.
Foresti
Elisabetta
E
Dipartimento di Chimica G. Ciamician, Università di Bologna, via Selmi, 2. 1-40126 Bologna, Italy.
Palmieri
Gianni
G
Petrini
Marino
M
Profeta
Roberto
R
D000447:Aldehydes / Q000737:chemistry; D000478:Alkylation; D000586:Amination; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D000838:Anions / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009595:Nitroparaffins / Q000737:chemistry*; D013237:Stereoisomerism; D013450:Sulfones / Q000737:chemistry*; D013816:Thermodynamics
D000447:Aldehydes; D000596:Amino Acids; D000838:Anions; D009595:Nitroparaffins; D013450:Sulfones; D008697:Methane; C008640:nitromethane