Glucose, acetic anhydride reaction oxidation

Another highly versatile building block derived from diacetone-glucose 54 is the 1,2-acetonide of 3-C-methyl-a-D-allose in its furanoid form 57, which has been utilized as the key compound in a convergent total synthesis of ACRL Toxin I (63). Its elaboration from 54 starts with a pyridinium dichromate / acetic anhydride oxidation (64), is followed by carbonyl olefination of the respective 3-ulose with methyl (triphenyl)phosphonium bromide and hydrogenation (— 55 56), and is completed by acid cleavage of the 5,6-isopropylidene group. This four-step process 54 -> 57, upon optimization of reaction conditions and workup procedure, allows an overall yield of 58 % (63), as compared to the 22 % obtained previously (65). 

In 2010, the Sato group disclosed the synthesis of tetrodotoxin 86 starting from d-glucose, in which the Perrier carbocyclization of enol acetate 92 was employed for the construction of the cyclohexane core of tetrodotoxin. 4,6-O-Benzylidene derivative 99 was converted into pyranoside 93 possessing an exo-methylene group at C-3 (Scheme 12.47). m-CPBA oxidation of 93 stereoselectively provided epoxide 183. Alkaline hydrolysis of the epoxide in 183 followed by acetonide formation gave primary alcohol 184. Oxidation of 184 afforded aldehyde 185, which was converted into (Z)-enol acetate 92 by the action of acetic anhydride and potassium carbonate. When enol acetate 92 reacted with Hg(OAc)2, followed by NaCl treatment, the Perrier carbocyclization reaction successfully took place to afford a mixture of... 

Diacetone allose can be formed from diacetone glucose by first oxidizing die C-3 hydroxyl carbon with acetic anhydride in dimethylsulfoxide [101], followed by reduction with sodium borohydride (reaction 4.95). The reduction forms exclusively the allose configuration. 

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