(1) Monoacetone-d-mannose was now obtained as colourless crystalline needles and its structure was established as 2,3-monoacetone-d-mannofuranose (III). Melting point, 80.5–82°. [α]D15=+4.5° (5 minutes)→−3.7° (40 hours) in water. And triaeetyl-monoacetone-d-mannose was ascertained to have the constitution (VI). (2) Bis-phenylhydrazone of d-lyxo-trihydroxy-glutarie dialdehyde was obtained as colourless needles, starting from 2,3-monoacetone-d-mannofuranose. Melting point, 168.5–169°. [α]D15=−72° in pyridine. Equilbrium rotation of d-lyxo-trihydroxy-glutaric dialdehyde was measured. [α]D15=+5° in water. Bis-p-nitrophenylhydrazone of d-lyxo-trihydroxyglutaric dialdehyde was obtained as orange-yellow leaflets. Melting point, 207–207.5°. Strontium salt of d-lyxo-trihydroxy-glutaric acid was obtained by oxidizing the dialdehyde with bromine in presence of strontium carbonate.
Although paulownia wood is very soft, its lignin belongs to so-called hard-wood lignin, and it contains both syringyl and guaiacyl radicals. These facts are established by the measurements of the lignin content and of the methoxyl value of the paulownia wood lignin, and by the ethanolysis and oxidation with nitrobenzene.