171. Asymmetric Synthesis of α-Amino Acids and α-N-Hydroxyamino Acids from N-Acylbornane-10,2-sultams: 1-chloro-1-nitrosocyclohexane as a practical [NH₂⁺] equivalent
     Oppolzer, W.; Tamura, O.; Deerberg, J.
     Helv. Chim. Acta 1992, 75, 1965-1978

Successive treatment of N-acylsultams 3 with sodium hexamethyldisilazide, 1-chloro-1-nitrosocyclohexane (1), and aq. HCl gave diastereoisomerically pure, crystalline N-hydroxyamino-acid derivatives 5. These were converted into various amino acids 7, N-hydroxyamino acids 8, and an N-Boc-amino acid 9. (S, S)-Isoleucine (17) and (S, S)-2-acetamido-3-phenylbutyric acid (23) were obtained from N-crotonoylsultam 15via 1,4-addition of an organomagnesium or organocopper reagent followed by enolate ‘amination’ with 1.

DOI : 10.1002/hlca.19920750622 

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