85193-86-8Relevant articles and documents
SACCHARIDE (2,4-DICHLOROPHENOXY)ACETYLHYDRAZONES, THE MECHANISM OF HETEROCYCLIZATION UNDER ACETYLATIVE CONDITIONS
El Ashry, El Sayed H.,El Kilany, Yeldez,Abdallah, Abdallah A.,Mackawy, Kamel
, p. 273 - 280 (1983)
The synthesis of the (2,4-dichlorophenoxy)acetylhydrazones of a number of monosaccharides is described.The reaction of the corresponding D-galactose derivative with acetic anhydride in pyridine was investigated.Penta-O-acetyl-aldehydo-D-galactose (2,4-dichlorophenoxy)acetylhydrazone was prepared by reaction of the hydrazine with penta-O-acetyl-aldehydo-D-galactose, and its 1H-n.m.r. spectrum indicated its existence as two geometric isomers.Reaction of the pentaacetate with boiling acetic anhydride caused its acetylative heterocyclization into 3-acetyl-5--2-(1,2,3,4,5-penta-O-acetyl-D-galacto-pentinol-1-yl)-1,3,4-oxadiazoline.A generalized mechanism for the heterocylization , based on "soft" and "hard" acids and bases, is discussed.D-arabino-Hexos-2-ulose 2-(2,4-dichlorophenoxy)acetylhydrazone 1-phenylhydrazone was also prepared.