Reductive Transformations of Polyfunctional Nitro Compounds: Synthesis of Methyl 7-Aminoalkanoates and Five-Membered Cyclic Nitrones - Inter- and Intramolecular 1,3-Dipolar Cycloadditions
✍ Scribed by Zschiesche, Ruth ;Reißig, Hans-Ulrich
- Book ID
- 102900321
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 788 KB
- Volume
- 1989
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
Alkanoates, 7-amino / Cycloadditions, 1,3-dipolar / Nitrones, cyclic / Reduction of nitro compounds In preceding reports we described efficient syntheses of polyfunctional nitro alkanes') and their conversions into 1,4,7-tricarbonyl compounds3). This concept allows shortcut entries into several classes of natural products3). Since transformations of nitro groups to other nitrogen-containing fun~tionalities~) are also possible, we examined some of these methods with nitroalkanes as 1 or 5. The resulting products, for instance uncommon amino acid derivatives or functionalized heterocycles, should be of general interest.
Synthesis of Methyl 7-Aminoalkanoates
Ammonium formate is able to transfer hydrogen in the presence of catalytic amounts of palladium on carbon5). Ram and Ehrenkaufer6) published a method for smooth reduction of nitro compounds to the corresponding amines using this reagent. Applying this method to the acetals 1 and 3, the expected methyl 7-amino-4,4-(ethylenedioxy)al-NO2 NH2 1 R-H 73 % 2 3 R-Me 94 % 4 *I In this discussion the numbering for monocyclic isoxazole derivatives is employed to facilitate comparison with other results.
In the experimental part the systematic IUPAC numbering is applied.