Asymmetric Synthesis ofα-Methylα-Amino Acids by Diastereoselective Alkylation of Optically Active 6-Isopropyl-3-methyl-2,3—dihydro-6H-1,4-oxazin-2-ones

1997 ◽  
Vol 36 (9) ◽  
pp. 995-997 ◽  
Author(s):  
Rafael Chinchilla ◽  
Larry R. Falvello ◽  
Nuria Galindo ◽  
Carmen Nájera
Keyword(s):  
Amino Acids ◽  
Asymmetric Synthesis ◽  
Optically Active

Isoxazolinium Salts in Asymmetric Synthesis. 1. Stereoselective Reduction Induced by a 3’-Alkoxy Stereocentre. A New Approach to Polyfunctionalized β-Amino Acids* [1, 2]

2004 ◽  
Vol 59 (4) ◽  
pp. 451-467 ◽  
Author(s):  
Marco Henneböhle ◽  
Pierre-Yves Le Roy ◽  
Matthias Hein ◽  
Rudolf Ehrler ◽  
Volker Jäger
Keyword(s):  
Amino Acids ◽  
Asymmetric Synthesis ◽  
Catalytic Hydrogenation ◽  
Optically Active ◽  
Side Chain ◽  
Reduction Step ◽  
One Pot ◽  
New Approach ◽  
Stereoselective Reduction

AbstractA new approach to optically active N-methylamino acids is presented, relying on stereoselective reduction of N-methylisoxazolinium salts with a dioxyethyl side-chain. The diastereoselectivity of the reduction step is studied systematically, in comparison with that of respective isoxazolines. A two-step transformation of isoxazolinium salts - with NaBH3(OAc) and subsequent catalytic hydrogenation as well as a one-pot reduction by catalytic hydrogenation led to high (95:5 and 87:13) diastereomeric ratios of protected erythro-N-methylaminopentanetriols. The hydroxyethyl side-chain is elaborated by oxidation to afford the β -N-methylamino acid 37, exemplifying the potential of this strategy.

Sign in / Sign up

Export Citation Format

Share Document