Mr Fenton, Oxidation in Presence of Iron. 365 



other properties with jB-acrosazone (Fenton and Jackson, B. A. 

 Report, 1899). Later, Jackson {Trans. Ghent. Soc. 1900. 129) 

 by similar treatment found also an osazone closely resembling 

 a-acrosazone. 



It is not improbable that glycollic aldehyde may be produced 

 as an intermediate stage in the formation of ' formose ' from 

 formaldehyde, and that the two condensation products may be 

 identical ; this suggestion is supported by the fact that Pechmann 

 {Ber. 1897. 2459) has obtained glyoxalosazone from formaldehyde 

 and accounts for its formation by the aldol condensation of form- 

 aldehyde to glycollic aldehyde. 



Degradation of Sugars. 

 [Trans. Chem. Soc. 1900. 1294.] 



The direct and systematic transformation of a higher to a lower 

 member of the aldose sugars was first effected by Wohl [Ber. 1893. 

 740 et seq.]. The oxim of the sugar is first obtained by the action 

 of free hydroxylamine and is then acted upon by acetic anhydride 

 in presence of sodium acetate. In this way the nitrile of the 

 corresponding acid results and all the hydroxyl groups become 

 acetylated. Glucoseoxim for example yields the nitrile of pent- 

 acetylgluconic acid, and arabinoseoxim gives the nitrile of tetr- 

 acetyl arabonic acid. These products readily lose the elements of 

 hydrocyanic acid by the action of silver oxide or of alkalis yielding 

 a derivative of the lower sugar. 



This method has now been applied in the case of glycollic 

 aldehyde. Alcoholic hydroxylamine gives the corresponding oxim 

 in a syrupy and impure condition, but when the product is treated 

 with acetic anhydride as in Wohl's experiments it gives the acetyl 

 derivative of glycollic acid nitrile, or acetoxyacetonitrile, 



CH 3 CO . O . CH 2 CN. 



This when treated with ammoniacal silver oxide yields a product 

 which when acted upon by dilute sulphuric acid gives formalde- 

 hyde. Wohl has since obtained glycollic aldehyde from glyceral- 

 dehyde, so that only the degradation of tetrose to triose is 

 wanting to complete the entire series from hexose. 



A second systematic method of bringing about the degradation 

 of sugars is that based upon the oxidation of the corresponding 

 acids by hydrogen dioxide in presence of iron. This was first 

 effected in case of tartaric acid, a normal oxidation-product of 

 tetrose, in the manner described above ; the degradation here 

 extends over two stages — tetrose to diose — and an intermediate 

 product — dioxymaleic acid — can be isolated. The initial operation 



