Olefins, cyclo-

RUBBERY CYCLO-OLEFIN (CYCLO-ALKENE) POLYMERS... 

Rubbery Cyclo-olefin (Cyclo-alkene) Polymers 305... 

Accordingly, work has been done on series of n-paraffins,. isoparaffins, naphthenes, aromatics, and naphthene-aromatics which have been chosen as representative of the major components of petroleum. In addition, olefins, cyclo-olefins, and aromatic olefins have been studied as a means of depicting the important secondary reactions of the copious amounts of unsaturates produced in the majority of catalytic cracking reactions. A silica-zirconia-alumina catalyst was used principally it resembles closely in cracking properties typical commercial synthetic silica-alumina catalysts. 

Another synthetic approach to p.-methylene complexes originates from the very simple idea that there might be an analogy with olefin cyclo-propanation (146) in organometallic chemistry if one had starting materials at hand that contain metal-metal double bonds (147). This type... 

Isoxazoles and isoxazolidines fused with sugar systems are found to show biological activity. In a continuation of our studies on the utilization of a variety of protocols on the sugar-derived chirons we embarked onto the 1,3-dipolar cycloaddition reactions. Accordingly, intramolecular oxime olefin cyclo-addition (lOOC) reactions on the chiron (91 X=NOH) gave an isoxazolidine-fused saccharide (92) (Scheme 22.21). 

CHI CsHii-n with zinc powder and ammonium chloride in aqueous ethanol or hot ethanolic sodium ethoxide yields the alkane n-C7Fi5 C7Hj5-n and the olefin n-C7Fi5 CH=CH C5Hu-n, respectively. The results of detailed studies on free-radical (AZBN-initiated at 70 °C) addition of perfiuoroalkyl iodides across C=C bonds in cyclic olefins (cyclo-pentene, -hexene, and... 

Allyl compounds have been converted to Ti-ethylenic complexes by protonation with acids (2-25). As shown in the reaction, an olefin-cyclo-pentadienyl complex is formed. 

The stability constants of a great number of mono- and polyolefin complexes of silver nitrate have been determined by gas chromatographic studies. The results of these studies are summarized in Table 6-4. These observations can be utilized for isolation and purification. For example, trans-cycio-octem is separated from the m-isomer by the preferential formation of the more stable fr 2n5-cyclo-octene silver complex. The very strained olefin, cyclo-propene, is quantitatively removed from a mixture of olefins by passing it with nitrogen through an aqueous silver nitrate solution. 

A number of cumulene-olefin cyclo-additions appear to be non-concerted, notably when hetero-atoms are present and the 1,4-dipolar zwitterionic intermediates are likely to be stabilized. Reaction (6.68), although concerted, shows some of this character since the isomeric cyclobutanone is not produced. The presence of hetero-atoms is not essential to a stepwise mechanism. 

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