Isolation of some precursors of 2-methylpyrrole in the Elson-Morgan reaction.
1-C-(1-Acetylacetonyl)-2-deoxy-2-(1-methyl-3-oxobut-1-enyl)amino -d-galactitol is obtained from the condensation of 2-amino-2-deoxy-d-galactose with pentane-2,4-dione in anhydrous solvent. On treatment with hot alkali it gives 2-methylpyrrole with 37% yield. By acid hydrolysis under mild conditions the compound loses the N substituent and from the resulting unstable derivative 2-methylpyrrole is obtained (52% yield). It is concluded that derivatives of aminohexoses substituted at C-1 with a dioxopentyl chain are the precursors of 2-methylpyrrole in the Cessi & Serafini-Cessi (1963) modification of the Elson-Morgan reaction. As demonstrated previously, products of condensation of aminohexoses with pentane-2,4-dione at the amino group are not converted directly into 2-methylpyrrole, but this step provides protection of the amino group during condensation at C-1.
D000143:Acids; D000468:Alkalies; D000588:Amines; D000605:Amino Alcohols / Q000138:chemical synthesis; D002854:Chromatography, Paper; D005690:Galactose; D006595:Hexosamines / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007659:Ketones; D000432:Methanol; D011758:Pyrroles / Q000138:chemical synthesis*; D013057:Spectrum Analysis
D000143:Acids; D000468:Alkalies; D000588:Amines; D000605:Amino Alcohols; D006595:Hexosamines; D007659:Ketones; D011758:Pyrroles; D005690:Galactose; D000432:Methanol