RILEY Selenium dioxide oxidation

Selenium dioxide oxidation of ketones and aldehydes (Riley, 1932) O 

substituted alkyl and aryl R = alkyl, aryl n = 1-3 

In the laboratory of T.-J. Lu, a highly stereoselective method for the asymmetric synthesis of a-amino acids was developed by the alkylation of a chiral tricyclic iminolactone derived from (+)-camphor. The iminolactone can be considered a glycine equivalent. The synthesis commenced with the Riley oxidation of (+)-camphor to obtain the corresponding (+)-camphorquinone. Amino acids are obtained by first alkylating the a-position of the lactone with various alkyl halides and then hydrolyzing the monosubstituted products. The advantage of this technique was that the chiral auxiliary could be fully recovered without the loss of any optical activity. 

The first total syntesis of cristatic acid, a potent antibiotic against Gram-positive bacteria, was reported by A. Furstner et al. The prenylated aromatic substrate (trisubstituted gem-dimethyl alkene) was subjected to a Se02-catalyzed allylic oxidation to obtain stereospecifically the ( )-allylic alcohol. 

During the enantioselective total synthesis of miroestrol by E.J. Corey and co-workers, the introduction of a hydroxyl group was required at one of the bridgehead positions. This position was a to a ketone and was also the allylic position to a double bond. The oxidation was effected by selenium dioxide/fert-butyl hydroperoxide at 25 °C. 

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Riley selenium dioxide oxidation Oxidation of the methylene group adjacent to a carbonyl group or the double bond of olefins (allylic or benzylic position) with Se02. 380... 

REIMER TIEMANN Phenolformylation 314 REISSERT - GROSHEINTZ FISCHER Cyanoamme reaction 315 REPPE Acetylene reaction 316 von RICHTER Aromatic earboxylation 317 von RICHTER - WIDMAN - STOERMER Cmnotme synthesis 318 RILEY Selenium dioxide oxidation 319 Rimnt 4... 

In 23-30 per cent yield by the oxidation of ethyl malonate with selenium dioxide. Astin, Newton, and Riley, J. Chem. Soc. 1933, 391 Ml-ller, Ber. 66, 1668 (1933)-... 

Oxidation. Use of selenium dioxide for the oxidation of reactive methylene groups to carbonyl groups was introduced by H. L. Riley, Morley, and Friend. A procedure developed by H. A. Riley and Gray for the preparation of phenyl-glyoxal calls for heating a solution of acetophenone in dioxane with either selenious acid, or equivalent amounts of selenium dioxide and water, and stirring the mixture... 

Riley oxidations. Oxidations of organic compounds with selenium dioxide, e.g., the oxidation of active methylene groups to carbonyl groups. 

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