β-Lactams fromD-Erythrose-Derived Imines: A Convenient Synthesis of 2,3-Diamino-2,3-dideoxy-D-mannonic-Acid Derivatives
作者:Thomas Storz、Bruno Bernet、Andrea Vasella
DOI:10.1002/(sici)1522-2675(19991215)82:12<2380::aid-hlca2380>3.0.co;2-p
日期:1999.12.15
The D-manno-configured N-anisylated beta-lactam 40, the beta-lactam carboxylic acids 4 and 43, and the corresponding phosphonic-acid isosters 49 and 50 have been synthesized from D-glucose in 8-10 steps, respectively None of these compounds exhibited a significant inhibitory activity in vitro against the sialidases of Vibrio cholerae, Salmonella typhimurium, Influenza A (N9), and Influenza B virus. Cycloaddition of the in situ generated imines derived from the D-erythroses 6, 16, and 17 with the ketene: from mesyloxyacetyl chloride (20) gave the 2-mesyloxy-D-hexono-1,3-lactams 25, 27a/b, 28a/b/c, and 29 in 23, 69, 57, and 90% yield, respectively (Scheme 3). Transformation of 27a/b and 29 (> 85%) to the corresponding azides, followed by oxidative N-deprotection, gave 30a/b (45%) and 34 (80%). Subsequent alkylation of the ring N-atom in 31a with benzyl bromoacetate and dibenzyl (triflyloxymethyl)phosphonate 46 gave the carboxylate 41 (77%) and the phosphonate 47 (55%; Schemes 4 and 5). Hydrogenolysis of 41 gave the beta-lactam amino acid 43, besides its hydrolysis product 44. Reductive N-acylation of the azido group in 41 (93%), followed by hydrogenolytic debenzylation, yielded the 2-trifluoroacetamido N-(carboxymethyl)-beta-lactam 4 (56%). Similarly, 47 gave the 2-trifluoroacetamide 48 (89%), and hence, the 2-amino-N-(phosphonoylmethyl)-beta-lactams 49 (40%) and 50, resulting from deacylation of 49 (14%). Aminolysis and carbamoylation of the protected beta-lactams 31a and 35 led to the 2,3-diamino-2,3-dideoxy-D-mannonamides 51 and 53, respectively (Scheme 6).