Formose Reactions. XXI. A Selective Formation of Dihydroxyacetone in the Formose Reaction in N,N-Dimethylformamide

Article abstract of DOI:10.1246/bcsj.57.2761

Dihydroxyacetone (DHA) was obtained in good yield from the selective formose reaction which was conducted with 2-(dimethylamino)ethanol and vitamin B₁ in N,N-dimethylformamide (DMF).The major products were isolated from the formose and identified as dihydroxyacetone and 2-(1,2-dihydroxyethyl)-5-(2-hydroxyethyl)-4-methylthiazole by spectral data.Vitamin B₁ suppressed the vaporization of formaldehyde from the reaction solution.Irrespective of the 2-(dimethylamino)ethanol concentration (above 0.1 M (1M=1 mol dm^-3)), the maximum yield of DHA was 80-90 glcpercent at 1.0 M formaldehyde concentration, when the formaldehyde consumption was above 90percent.Above 3.0 M formaldehyde concentration, selective formation of DHA (above 80 glcpercent) was obtained at he early stage of the reaction.The scheme for the formation of DHA in the formose reaction in the presence of vitamin B₁ was also proposed.