Albright-Goldman oxidation

The Albright-Goldman oxidation is a name reaction in organic chemistry that was first described in 1965 by the American chemists J. Donald Albright and Leon Goldman . It is particularly suitable for the synthesis of aldehydes from primary alcohols . Analogously, secondary alcohols to ketones oxidize . Dimethyl sulfoxide / acetic anhydride serves as an oxidizing agent .

Overview reaction

The Albright-Goldman oxidation enables a mild oxidation of primary alcohols to aldehydes. In contrast, there is no further reaction to the corresponding carboxylic acids :

The oxidation of secondary alcohols produces ketones in this way:

In both reactions, R stands for an organic residue . During the oxidation of the secondary alcohol, other alkyl or aryl groups can also be present instead of the methyl group marked in green .

Reaction mechanism

A possible reaction mechanism for the Albright-Goldman oxidation of a primary alcohol to the corresponding aldehyde according to the first overview reaction is described below:

First, dimethyl sulfoxide 1 reacts with acetic anhydride to form a sulfonium ion . Then the carried addition of the primary alcohol. In addition, acetic acid is split off, so that intermediate stage 2 is formed. Finally, this reacts to form the aldehyde , splitting off acetic acid and dimethyl sulphide.

Sample reaction

The Albright-Goldman oxidation is a particularly mild oxidation process. This makes it suitable for the oxidation of compounds such as indole alkaloids , which are sensitive to non-selective oxidizing agents. This reaction can also be used in the case of sterically hindered hydroxyl groups . An exemplary application is the oxidation of the indole alkaloid yohimbine :

Atomic economy

In the Albright-Goldman synthesis, stoichiometric amounts of dimethyl sulfoxide and acetic anhydride are used to oxidize the alcohols . Dimethyl sulfide and acetic acid are produced as waste materials. At the same time, the product of the reaction (aldehyde or ketone) has a lower number of atoms than the alcohol used. Accordingly, the lower the molar mass of the alcohol used, the worse the atom economy of this reaction .

Individual evidence

^ J. Donald Albright, Leon Goldman: Indole Alkaloids. III.1 Oxidation of Secondary Alcohols to Ketones . In: The Journal of Organic Chemistry . tape 30 , no. 4 , 1965, pp. 1107-1110 , doi : 10.1021 / jo01015a038 .
↑ Zerong Wang: Comprehensive organic name reactions and reagents Volume 1 . John Wiley, Hoboken (NJ) 2009, ISBN 978-0-470-28662-3 , pp. 33-36 .
^ J. Donald Albright, Leon Goldman: Dimethyl sulfoxide-acid anhydride mixtures for the oxidation of alcohols . In: Journal of the American Chemical Society . tape 89 , no. 10 , 1967, p. 2416-2423 , doi : 10.1021 / ja00986a031 .

Web links

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[1] J. Donald Albright, Leon Goldman: Indole Alkaloids. III.1 Oxidation of Secondary Alcohols to Ketones . In: The Journal of Organic Chemistry . tape 30 , no. 4 , 1965, pp. 1107-1110 , doi : 10.1021 / jo01015a038 .

[2] Zerong Wang: Comprehensive organic name reactions and reagents Volume 1 . John Wiley, Hoboken (NJ) 2009, ISBN 978-0-470-28662-3 , pp. 33-36 .

[3] J. Donald Albright, Leon Goldman: Dimethyl sulfoxide-acid anhydride mixtures for the oxidation of alcohols . In: Journal of the American Chemical Society . tape 89 , no. 10 , 1967, p. 2416-2423 , doi : 10.1021 / ja00986a031 .