Cornforth

Pure, discrete diethylene, triethylene and tetraethylene glycols are all commercially available from a variety of sources. Pentaethylene glycol and longer polyoxyethylene glycols are generally prepared by condensation of two equivalents of a shorter glycol with a diol dichloride or ditosylate. Such methods have been reported by Pedersen", Cornforth , and Krespan . The approach is illustrated in Eq. (7.1), below. 

The ready reduction of iodohydrins is utilized in the Cornforth reaction for preparing olefins from epoxides. Here the opening and reduction are carried out in one step by treatment of the epoxide, in an acetic acid-sodium acetate buffer, with sodium iodide and zinc. A less common use of iodohy-drin reduction is illustrated in the synthesis of the diene (127) ... 

J. W. Cornforth (Sussex) stereochemistry of enzyme-catalysed reactions. 

The Cornforth rearrangement involves the thermal interconversion of 4-carbonyl substituted oxazoles, with exchange between the C-C-O side-chain and the C-C-O fragment of the oxazole ring. These reactions generally involve compounds where a heteroatom (-OR, -SR, -Cl) is attached to the 5-position (R2) of the starting oxazole. 

Cornforth reported in 1949 that 2-phenyl-5-ethoxyoxazole-4-carboxamide (3) rearranged on heating to ethyl 2-phenyl-5-aminooxazole-4-carboxylate (4). ... 

The isolation in poor yield of 2,5,5-triphenyl-4(5f )-oxazolone (82) by reaction of benzilic acid with benzonitrile in concentrated sulfuric acid was claimed by Japp and Findlay. Cornforth, however, suggested that the reactions of this product, m.p. 136°, could be accounted for more satisfactorily by the isomeric 5(4i ) structure 83. 

Sir John Warcup Cornforth (1917-2004) was born in Sydney, Australia, and earned his Ph.D. from Oxford University in 1941 working with Sir Robert Robinson. He was on the staff of the National Institute for Medical Research in London from 1946 to 1962, at Shell Research Ltd. (1962-1975), and ultimately at Sussex University (1975-1982). Profoundly deaf since his teens, he worked in constant collaboration with his wife, Rita Harradence. He received the 1975 Nobel Prize in chemistry. 

These results may be explained either by Cram s cyclic model in the case of lithium alkyls or by Cornforth s dipolar model if copper-boron trifluoride reagents are used. Boron trifluoride causes double complexation of both nitrogen and oxygen atoms which results in the formation of an adduct with rigid antiperiplanar conformation due to electrostatic repulsion (see 4 and 5)9. 

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