Mr Jackson, On the condensation of formaldehyde, etc. 117 



On the condensation of formaldehyde and the formation of 

 /3-acrose. By Henry Jackson, M.A., Downing College. 



[Received 18 February 1901.] 



An aqueous solution of formaldehyde, obtained by boiling 

 paraformaldehyde, was treated with basic lead carbonate and 

 heated on a water bath for one hour. After filtering it was 

 evaporated in vacuo at 50° C. and the syrup treated with a mixture 

 of methyl and ethyl alcohols. The insoluble lead salt was sepa- 

 rated and the alcohol distilled off from the sugar. A two per 

 cent, aqueous solution of the sugar was heated with phenyl 

 hydrazine acetate on the water bath for four hours. The crude 

 osazone was boiled with water; and acrosazone (Fischer and 

 Passmore, Ber. 1899) remained undissolved. The filtrate from 

 this on cooling deposited a mass of fine yellow crystals. These 

 were re-crystallised twice again from hot water. This was found 

 to be a mixture of osazones which have been separated by a long 

 series of fractional precipitations into the following : 



(i) Readily soluble in ether and benzene, ethyl acetate and 

 ethyl alcohol. Melting point 131°— 136°. 



(ii) Sparingly soluble in ether and benzene, soluble in ethyl 

 acetate. Melting point 158°. This appears identical with the 

 /3-acrosazone obtained by the condensation of glycollic aldehyde 

 (Fenton and Jackson, Rep. Brit. Ass. 1900; Jackson, J. G. S. 1900) 

 and of glycerose (Fischer and Tafel, Ber. 1887 ; Wohl, Ber. 1900). 



(iii) Sparingly soluble in most solvents, but may be re-crystal- 

 lised from methyl alcohol. Melting point 194° — 196°. 



