| Research Abstract |
Nikkomycin Bz, a dipeptide antibiotic, posseses γ-hydroxy-α-amino acid as the N-terminal amino acid and a nucleoside amino acid as the C-terminal amino acid.
1) α-Allyloxycarbonylnitrone having a sugar auxiliary was explored. Using this method, the N-terminal amino acid moiety was synthesized.
2) (5R) [and (5S)]-5,6-Dihydro-5-phenyl-2H-1, 4-oxazin-2-one N-oxides were designed and synthesized as the chiral (E)-geometry-fixed α-alkoxycarbonylrtitrones. The key intermediate of carbocy polyoxin C, the carbocyclic analogue of the C-terminal amino acid, was synthesized by employing 1,3-dipolar cycloaddition of the cyclic nitrone.
3) Nucleophilic addition reaction of 2-trimethylsilyloxyfurah to N-Gulosyi-C-alkoxymetnyl-nitrones was explored. The key intermediate of polyoxin C, the C-terminai amino acid of nikkomycin Bz, was synthesized by employing this method.
4) Methods mentioned above were applied to the synthesis of highly functionalized anti- and syn-β-substituted α-amino acids.
5) Highly stereoselective cycloaddition of (5S)-5,6-dihydro-5-phenyl-2H-1 ,4-oxazin-2-one N-oxide with allyll alcohol in the presence of MgBr_2 was applied to the synthesis of an antibiotic clavalanine.
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