WEERMAN Degradation

WEERMAN DEGRADATION. Formation of an aldose with one less carbon atom from and aklonic acid by a Hoffmann-type rearrangement of the corresponding amid. This is a general reaction of a-hydroxycarboxylic acids. 

Aldonamides having five or more carbon atoms in the sugar chain are hydrolyzed in aqueous solution with accompanying mutarotation84 but those of tetronic acids are, however, stable.85 Lower sugars may be prepared from aldonamides by the Weerman degradation method. 

WEERMAN Degradation 405 WEIDENHAGEN Imidazole synthesis 406 WEINREB Ketone synthesis 407 WEISS Annulation 408 WENCKER AZsidsie synthesis 409 WENZL-IMAMOTO Reduction 4t0... 

The Weerman degradation was employed in one of the first preparations of dialdoses, namely of n-f/ireo-tetrodialdose, using the diamide of D-glucaric acid as starting material. An inosose has been degraded to a pentodialdose by way of its disulfone and the Nef reaction, transformation of a 6-deoxy-... 

This reaction is related to Curtius Rearrangement, Lossen Rearrangement, Schmidt Reaction, Weerman Degradation, and Wolff Rearrangement. 

The preceding sequence (called the Weerman degradation) achieves the same end as what procedure described in this chapter ... 

The application of the Hofmann and Curtius rearrangement to the preparation of 2-thienvb)cetaldehyde (55) was studied, utilizing the degradation employed by Weerman. These reactions could be represented as follows ... 

Aldonamides having free hydroxyl groups at C-2 are degraded to the aldose having one less carbon atom by treatment with hypochlorites. This is the basis of the Weerman method of degrading aldoses (see Ref. 1, Chapter 3). 

Trimethyl-D-arabofuranose (XXV) has been prepared by the degradation of 2,3,4,6-tetramethyl-D-gluconamide (XXIII) by the action of sodium hypochlorite (Weerman reaction), the cyclic urethane (XXIV) undergoing hydrolysis with dilute sodium hydroxide solution in the cold.80... 

This reaction is related to the Weerman Reaction, Wohl Degradation, and Fenton... 

The Hofmann method for the degradation of amides to the amines of one less carbon was applied by Weerman 198) to the amides of a-hydroxy acids and led to the production of aldehydes with one carbon less than the original acid ... 

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