Chromic anhydride oxidation diacetate

By oxidation of the methyl derivative of an aromatic hydrocarbon with a solution of chromic anhydride in acetic anhydride and acetic acid. The aldehyde formed is immediately converted into the (/m-diacetate, which is stable to oxidation. The diacetate is collected and hydrolysed with sulphuric acid, for example ... 

The 6a-hydroxyl group in ty-muricholic and hyocholic acid was verified by the identification of hyodeoxycholic acid derived from these trihydroxy acids. After acetylation in a mixture of acetic anhydride and pyridine at room temperature, hyocholic acid yielded a diacetate whereas cy-muricholic acid yielded both a diacetate and a triacetate. The diacetates were oxidized with chromic anhydride and an ethylenedithioketal was prepared, which after desulfuration with Raney nickel yielded hyodeoxycholic acid [Hsia et al. (45)]. 

This step proceeds through the hydroxy-7V-acetate (418), which undergoes rearrangement in acetic anhydride-sodium acetate to give the iV-acetyl-acetate (419). Further simple steps afforded 1,2-didehydroaldosterone 18,21-diacetate (420), permitting tritiation to produce radioactive-labelled aldosterone. Several oxidations of the nitrone (417) are also described Jones chromic acid in aqueous acetone... 

Methylnaphthalene is commonly used as a feedstock in the production of vitamia K3 (menadione). Methylnaphthalene is oxidized to menadione with chromic or nitric acid, in a similar method to anthracene oxidation. Menadione is used as an intermediate in the production of vitamin Ki.To produce vitamin Ki, menadione is reduced with hydrogen on Pd/activated-carbon catalysts to mena-diol. Esterification of the two hydroxyl groups with acetic anhydride yields mena-diol diacetate, which is converted into the 1-monoacetate with ammonia. Vitamin Ki (phytomenadione) is produced by the reaction of 1-menadiol monoacetate with phytol, using a BF3/ether complex as catalyst, followed by hydrolysis and dehydrogenation. 

Benzal halides are hydrolyzed to aldehydes via water and an iron catalyst. Aromatic aldehydes are also obtained by the partial oxidation of an aromatic side chain using chromic acid and acetic anhydride followed by hydrolysis of the diacetate. 

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