Irvine-Purdie methylation

Purdie (Irvine-Purdie) methylation. Exhaustive methylation of a methyl glycoside by repeated treatment with methyl iodide and silver oxide, followed by hydrolysis of the pentamethyl ether with dilute acid to yield the anomeric hydroxyl group. 

This reaction is related to Irvine-Purdie Methylation. 

Other references related to the Irvine-Purdie methylation are cited in the literature. 

Hunsdiecker Reaction Hydroboration Reaction Hydroformylation Reaction Ireland-Claisen Rearrangement Irvine-Purdie Methylation Isler Modification Ivanov Reaction... 

The Irvine-Purdie exhaustive methylation, which involves methyl iodide in the presence of Ag20... 

Purdie and Irvine used methyl iodide in presence of silver oxide in methylating sugars. W. C. Denham and H. Woodhouse used dimethyl sulphate and alkali in methylating cellulose, and the obvious step of using this method in methylating sugars and polysaccharides was taken by Haworth. ... 

The sequence of reactions leading to compound 83 by an elimination that liberates the aldehyde 82, which is immediately reduced to 83, is depicted. This result also explains the formation of 43 by Purdie-Irvine methylations of 4 (Ref. 29) and 33 (Ref. 24) in both, moist silver oxide is the base, and it initiates elimination followed... 

Irvine s first publication (1899) dealt with the rotatory powers of the optically active methoxy- and ethoxy-propionic acids prepared from lactic acid. In those early days the Purdie reaction afforded so rich a field for investigation that Irvine and his collaborators continued work on various types of hydroxy bodies in addition to the sugars. There appeared papers on the isopropylidene derivatives and methyl ethers of glycerol and mannitol, and on the chemistry of benzoin and benzoin-like materials. The constitution of the glucoside salicin was studied and its pentamethyl ether was synthesized. 

In Purdie and Irvine s method778 hydroxy compounds are alkylated by alkyl iodides in the presence of silver oxide. This method is of particular significance for methylation of carbohydrates, where, to avoid its oxidation, the reducing group is protected by glycosidation. 

Purdie-Irvine methylation of the residual hydroxyl group) afforded compound 94 (59%) that was treated with sodium hydroxide and then mineral acid to give the hydroxyacid 95. This last compound was prone to relactonisation and, thereby, regeneration of precursor 94. Nevertheless, when compound 95 was subjected to... 

Haworth originally devised the procedure of methylation in aqueous solution with dimethyl sulfate and sodium hydroxide [I] similarly, the method of benzylation [2] with benzyl chloride and powdered alkali hydroxide (with or without an additional solvent) and the old methylation procedure of Purdie and Irvine [3] are slow... 

American Viscose was the dominant rayon company at the time and well-puriBed dissolving grade wood cellulose was constantly improved thanks to fundamental research on methods of carbohydrate analysis. Purves had originally studied at St. Andrews University where Haworth, Hirst, Purdy and Irvine pioneered the methylation techniques which were essential for chemical structure determination. 

---