摘要 |
Disclosed are novel compounds represented by Structural Formula II, IX or XXVIII: R1, R21 and R22 are independently an aliphatic group, a substituted aliphatic group, an aromatic group or a substituted aromatic group. R2 is NR4R5 or N+=C-. Alternatively, R1 and R2, taken together with the methine group to which they are bonded, are a moiety represented by the following structural formula: R3 is NH2, OH, OC(O)H or OR9. R5, R6 and R7 are independently H or an amine protecting group. R8 is H, OH or OR8. R9 is an alcohol protecting group. Also disclosed are methods of preparing these compounds.
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