Reactions and Synthetic Applications

Reactions of Stabilized Arsonium Ylides with Carbonyl Compounds 

Huang et ol. (48) found that the carbomethoxymethylene triphenylar-sorane reacted with ketones as well as with aldehydes to give various unsaturated esters in good yield. The by-product, triphenylarsine oxide, can be removed by washing with dilute hydrochloric acid. A comparison 

TABLE 11 Comparison of Yields from the Reaction of Carbonyl Compounds Carbomethoxymethylene Triphenylarsorane and with the Corresponding Phosphonium Ylides WITH 

We found also that carbomethoxymethylene triphenylarsorane reacted with a series of aliphatic ketones under very mild conditions (47). For example, with acetone it reacted at room temperature, whereas with higher aliphatic ketones at their refluxing temperature (boiling point of the aliphatic ketones). The yields of the a,/3-unsaturated esters were moderate. 

On the basis of H-NMR and gas chromatographic analysis, it was shown that the product from aliphatic ketones in each case was a mixture of andZ isomers. Changing the solvent, molar ratio of reactants, reaction temperature, reaction time, or the presence of sodium bromide had little effect on the /Z ratio of reaction products. On the other hand, the structure of the substrate showed a profound effect, especially when a bulky tert-butyl group was adjacent to the carbonyl (see Table III). In this case 99% off olefinic compound was formed stereospecifically (46). 

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Meanwhile, Nikolay had started his new research on the preparation, reactions, and synthetic applications of p-chloro vinyl ketones and related compounds (p-aminovinyl ketones, p-kctoacetals). Efficient synthetic methods were developed and improved, including C-ketovinylation (introduction of the RCOCH = CH group), and a number of useful heterocyclic compounds (pyrazoles, triazoles, pyridines, and so on) were synthesized. The discovery of enamine-imine tautomerism in p-aminovinyl ketones was another remarkable achievement by Nikolay at that time. For these studies he received in 1953 the degree of Doctor of Science in chemistry. He continued as a lecturer and supervisor of postgraduates at the University, becoming docent (associate professor) in 1951 and full professor in 1955. 

H. Suginome, Reaction and synthetic application of oxygen-centered radicals photo-chemically generated from alkyl hypoio-dites in CRC Handbook of Organic Photochemistry and Photobiology, 2nd Edition, W. Horspool and F. Lenci (Eds.), pages 109-1-109-44 CRC Press 2004. 

Suginome, H., Reaction and Synthetic Application of Oxygen centered Radicals Photochemically Generated from Alkyl Hypohalites. In Horspool, W. M., Lenci, F. (eds), CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn, CRC Press LLC, Boca Raton, FL, 2004, Chapter 109, pp. 1 16. 

The present review concentrates mainly on the recent developments in the field of perfluoro- or polyfluoroalkanesulfonic acids and their derivatives including their syntheses, reactions and synthetic applications. Rf denotes a perfluoro alkyl or a polyfluoroalkyl group. 

D.G. Drueckhammer, J.R. Durrwachter, R.L. Pederson, D.C. Grans, L. Daniels, G.-H. Wong, Reversible and in situ formation of organic arsenates and vanadates as organic phosphate mimics in enzymatic reactions mechanistic investigation of aldol reactions and synthetic applications, I. Oi. Chem. 54 (1989) 70-77. 

Reaction and Synthetic Application of Oxygen-Centered Radicals Photochemically Generated from Alkyl Hypohahtes... 

Reactions and Synthetic Applications General. The for-mamide acetals enter into two main categories of reactions. 

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