US EPA

8313640 

Journal Article 

Dimethyl Sulfoxide-Trifluoroacetic Anhydride: A New Reagent for Oxidation of Alcohols to Carbonyls 

Omura, K; Sharma, AK; Swern, D 

1976 

Yes 

Journal of Organic Chemistry
ISSN: 0022-3263
EISSN: 1520-6904 

41 

6 

957-962 

English 

10.1021/jo00868a012 

Trifluoroacetoxydimethylsulfonium trifluoroacetate prepared in situ from dimethyl sulfoxide (Me2SO) and trifluoroacetic anhydride (TFAA) below -50 °C in methylene chloride reacts rapidly with alcohols to give alkoxydimethylsulfonium trifluoroacetates and trifluoroacetic acid. Addition of triethylamine (TEA) to the alkoxysulfonium salts gives carbonyl compounds, alkyl trifluoroacetates, and alkyl methylthiomethyl ethers in varying and controllable amounts depending on the structure of the alcohols and reaction conditions. Yields of carbonyls increase in the order primary < secondary < allylic and benzylic alcohols. Yields of carbonyls from primary and secondary alcohols are highest when TEA is added to the alkoxysulfonium salts at room temperature rather than below -50 °C, or when larger amounts of solvent are employed. Under optimum conditions, yields of carbonyls are in the range of 60% from primary alcohols, 80-85% from secondary alcohols, and 80-100% from benzylic and certain allylic alcohols. Under appropriate conditions, selective oxidation of primary and secondary hydroxyl groups can be effected in the presence of allylic or benzylic hydroxyl groups. Reaction pathways to account for product distribution are proposed. © 1976, American Chemical Society. All rights reserved.