Cyclohexyl radical structure

The latter, on reaction with methylamine yielded via the P-epoxide 373, the trans-a aminoalcohol 374, which was N-acylated to the amide 375. Acid-catalysed dehydration of the tertiary alcohol 375, led to the olefin 375, from which the key radical precursor, the chlorothioether377 was secured in quantitative yield by reaction with N-chlorosuccinimide. In keeping with the earlier results recorded for structurally related compounds, 377 on heating in the presence of ruthenium dichloride and triphenylphosphine also underwent a 5-exo radical addition to generate the cyclohexyl radical 378 which recaptured the chlorine atom to furnish the a-chloro-c/5-hydroindolone 379. Oxidation of thioether 379 gave the corresponding sulfoxide 380, which on successive treatment with trifluoroacetic anhydride and aqueous bicarbonate led to the chloro-a-ketoamide 381. The olefin 382 resulting from base induced dehydrochlorination of 381, was reduced to the hydroxy-amine 383, which was obtained as the sole diastereoisomer... 

The propagation step in this free radical polymerization has been demonstrated to involve radical attack on episulfide sulfur (as depicted above) by telomerization studies with cyclohexane. From the structures of the two major products, 20 and 21, cyclohexyl radical attacks at the sulfur atom by displacing fluoroalkyl radical. This new radical, a prototype of the growing polymer chain, then abstracts hydrogen from cyclohexane to form 20 or attacks another molecule of 6 (n = 1) at sulfur to give 21. 

Enantiomerically pure bis-Gp derivatives with chiral Gp ligands have been used with success in the catalytic enantioselective opening of meso-epoxides via electron transfer (see Section 4.05.8). The structural features are of relevance for the understanding of activity and selectivity of these complexes in diastereoselective reactions and for the design of novel catalysts. A comparison of the structure of three of these bis-Gp Ti derivatives (Scheme 481) in the solid state and in solution determined by X-ray crystallography and NMR methods indicated that the structures in the crystal and in solution are the same, and that applications of these complexes in catalysis can de discussed on the basis of crystallographic data.1114 In a similar study, the 1-methylcyclohexyl-Cp, 1-butyl-1-methylbutyl-Cp, and cyclohexyl-Cp titanocene dichlorides (Scheme 481) have been prepared and their molecular structures compared. The use of these three compounds in radical addition reactions has been studied.1115... 

Hydroxy Alkyl Phenyl Ketones The basic structures, 2-hydroxy-2-methyl-l-phenyl-1-propanone HAP and 1-hydroxy-cyclohexyl-1-phenyl ketone HCAP, are also well known [17] and still largely used (10.10) and studied [2i,f,18]. The para substitution of the benzoyl group (with an amino, an ether, or a thioether group) drastically changes the electronic transitions but does not significantly affect the reactivity of the derived benzoyl initiating radical. 

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