Chromic acid, oxidation alcohols

Obtaining the aldehyde is often difficult, since most oxidizing agents strong enough to oxidize primary alcohols also oxidize aldehydes. Chromic acid generally oxidizes a primary alcohol all the way to the carboxylic acid. 

H2Cr04 (chromic acid) to oxidize 1° alcohols to carboxylic acids ... 

Oxidations.1 The reagent compares favorably with N-haloamides and chromic acid for oxidation of secondary alcohols. Cyclohexanol is oxidized to cyclohexanone in 90-95% yield at room temperature. Less easily oxidized alcohols may require higher temperatures to initiate the free-radical reaction. The oxidation may become too vigorous if cooling is insufficient or if run on a large scale. 

The ester is given as having a molecular formula of CeHiaOa, which indicates each R (R ) is made of 2 carbons. Since chromic acid only oxidizes primary alcohols, the alcohol portion of the ester must be from propanol (CH3CH2CH2OH). This leaves only the acid propionic... 

Although primary alcohols are first oxidized to aldehydes, the aldehydes are further oxidized to carboxylic acids. The ability of chromic acid to oxidize aldehydes but not ketones is taken advantage of in a test that uses chromic acid to distinguish between aldehydes and ketones (see Experiment 52D). Secondary alcohols are oxidized to ketones, but no further. Tertiary alcohols are not oxidized at all by the reagent hence, this test can be used to distinguish primary and secondary alcohols from tertiary alcohols. Unlike the Lucas test, this test can be used with all alcohols regardless of molecular weight and solubility. 

The alcohol in this case is secondary. Chromic acid will oxidize the alcohol to give a ketone. 

Perkin, Sir William Henry (1838-1907) British organic chemist. Perkin became famous for his discovery of mauve, the first synthetic dye. This discovery originated in 1856 when Perkin attempted to synthesize quinine. He did not succeed in doing so. However, when he used chromic acid to oxidize toluidine he obtained a dark precipitate. When he repeated the experiment using aniline he again obtained a dark precipitate. He found that adding alcohol to this precipitate produced a bright... 

An optically active, secondary terpene alcohol. ( —)-Piperilol is found in various eucalyptus oils and (-l-) piperitol in the oil from a species of Andropogon. A somewhat viscous oil of pleasant smell. It yields piperitone on oxidation with chromic acid. 

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