Glucose 2-amino-2-deoxy-, reaction product with ethyl acetoacetate

The reaction of 2-amino-2-deoxy-D-glucose (D-glucosamine) with a dicarbonyl compound was carried out for the first time by Pauly and Ludwig,91 who were trying to discover how pyrrole rings in natural products are formed. They heated free D-glucosamine and ethyl acetoacetate on a steam bath and obtained a substance in which the presence of the pyrrole ring was demonstrated by the pine-splinter test. 

In the experiments first described, 2-amino-2-deoxy-D-glucose was heated with an excess of the /3-dicarbonyl compound in the absence of solvent. The product so obtained from ethyl acetoacetate, m.p. 142°, [a]n 49.7°, had an analysis corresponding to that for ethyl 2-methyl-5-(D-ara6mo-tetrahydroxybutyl)pyrrole-3-carboxylate and was considered to have this structure (1). In the reaction with 2,4-pentanedione, a material (m.p. 98°, Md — 25.1°) was obtained which was described as 3-acetyl-2-methyl-5-(D-ara5fno-tetrahydroxybutyl)pyrrole (2). Boyer and Furth" repeated the latter reaction, but in methanol solution, and obtained a product, m.p. 133°, whose analytical data were in agreement with those for structure (2). 

The reactions of amino glycoses with a variety of jS-dicarbonyl compounds have been studied systematically in aqueous acetone solution at neutral pH and room temperature. Under these conditions, well defined products are obtained, sometimes in yields as high as 90-100%. Using this technique, 2-amino-2-deoxy-D-glucose hydrochloride, plus the equivalent amounts of sodium carbonate and ethyl acetoacetate, gives a product (m.p. 142-143°, [a]D —25°) different from that obtained by Pauly and... 

The study of the reactions of amino sugars with /3-keto thiolesters was undertaken in order to obtain data on the way in which simple models of (S-acetoacetyl-Coenzyme A may react. There is no difference between the modes of reaction of ethyl thiolacetoacetate and ethyl acetoacetate with 2-amino-2-deoxy-D-glucose. In the reaction with l-amino-l-deoxy-o-fructose, the product (18) of the thiolester liberates ethanethiol very readily and forms the lactone (27). amino sugar interact, giving lactone (27). No compound similar to the pyrrole thiolester (18) was found. In this context, the investigation of similar reactions with acetamido sugars will be of interest. 

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