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Alcohol oxidation is a collection of oxidation reactions in organic chemistry that convert alcohols to aldehydes, ketones, carboxylic acids, and esters. The reaction mainly applies to primary and secondary alcohols. Secondary alcohols form ketones, while primary alcohols form aldehydes or carboxylic acids. [1] A variety of oxidants can be used.
For oxidations to the aldehydes and ketones, two equivalents of chromic acid oxidize three equivalents of the alcohol: 2 HCrO 4 − + 3 RR'C(OH)H + 8 H + + 4 H 2 O → 2 [Cr(H 2 O) 6] 3+ + 3 RR'CO. For oxidation of primary alcohols to carboxylic acids, 4 equivalents of chromic acid oxidize 3 equivalents of the alcohol. The aldehyde is an ...
The reaction uses a hypervalent iodine reagent [2] similar to 2-iodoxybenzoic acid to selectively and mildly oxidize alcohols to aldehydes or ketones. The reaction is commonly conducted in chlorinated solvents such as dichloromethane or chloroform. [2] The reaction can be done at room temperature and is quickly complete.
The Weinreb–Nahm ketone synthesis. The major advantage of this method over addition of organometallic reagents to more typical acyl compounds is that it avoids the common problem of over-addition. For these latter reactions, two equivalents of the incoming group add to form an alcohol rather than a ketone or aldehyde. This occurs even if the ...
The rate of the overall reaction depends on the slowest step, so the overall reaction will be first order when the reaction of the energized reactant is slower than the collision step. The half-life is independent of the starting concentration and is given by t 1 / 2 = ln ( 2 ) k {\textstyle t_{1/2}={\frac {\ln {(2)}}{k}}} .
An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration to give a conjugated enone. The overall reaction equation is as follows (where the Rs can be H)
The Henry reaction is a classic carbon–carbon bond formation reaction in organic chemistry.Discovered in 1895 by the Belgian chemist Louis Henry (1834–1913), it is the combination of a nitroalkane and an aldehyde or ketone in the presence of a base to form β-nitro alcohols.
The reaction generated an alcohol 3 which was directly reacted without purification with PTSA to afford alkene 4 in 86% yield as a single isomer. Hydrogenation and a subsequent benzyl- deprotection of the alkene intermediate according to the reported procedure afforded (+)-biotin in 73% yield over two steps.