1 -aryl-2- cyclohexanol

Information concerning the chemistry of meso-ionic 3-alkyl- and 3-aryl-l,2,3,4-oxatriazol-5-ones (271) is limited, but further investigation may well be encouraged by reports of pronounced hypotensive activity. 3-Cyclohexyl-1,2,3,4-oxatriazol-5-one (271, R = cyclohexyl) is resistant to attack by dilute mineral acid, but warm concentrated sulfuric acid gives cyclohexanol and carbon dioxide. In contrast, acid hydrolysis of 3-phenyl-l,2,3,4-oxatriazol-5-one (271, R = Ph) yields phenyl azide. Meso-ionic 3-cyclohexyl-l,2,3,4-oxatriazol-5-one shows two unusual reactions its photoirradiation in benzene gives cyclohexanone and heating with diphenylacetylene )delds l-cyclohexyl-4,5-diphenyl-1,2,3-triazole (276) rather than the expected 2-cyclohexyl-4,5-diphenyl-1,2,3-triazole. 

Nonracemic tra s-2-[aryl(alkyl)thio]cyclohexanols with l/ ,2/ -configuration are prepared with modest to good enantioselectivity in high yield by reaction of 1,2-epoxycyclohexane with various thiols in dichloromethane at 25 °C catalyzed by zinc L-tartrate in a heterogeneous reaction103. 

The discovery of 1 -aryl-1 -dimethylamino-cyclohexanes resulted from a surrey of compounds in which aromatic and basic features, both critical structural requirements of opioid analgesics, but usually separated by two or three carbon atoms, are linked to the same quaternary carbon. The synthesis of these compounds yielded a series of highly potent opioids (e.g. 1-Benzyl-4-(4-bromo-phenyl)-4-dimethylamino-cyclohexanol), however none of them are in clinical use (Lednicer et al., 1981). 

In limited cases, electronically neutral aryl bromides also served as good substrates in the Pd-catalyzed C-0 bond formation with the tolBINAP/Pd-system. For example, 1 -bromonaphthalene was coupled with cyclohexanol in 65 % yield, Eq.(184). 

A similar reaction has been described for the preparation of thioethers with aryl-and alkylthiotrimethyl silanes.Ring-closure occurs with co-bromo-1,2-epoxyalkanes on the action of magnesium and lithium in the presence of Cul. By this means, cyclobutanol, cyclopentanol, and cyclohexanol can be prepared. (e.g. Eq. 294). 

Hydroxyphenylcyclohexanes Cyclohexanols—see Cahx[4]cyclohexanols Cyclohexanones—see Cahx [4] cyclohexanones Cyclohexenones—see Aryl-2-cyclohexenones 4-Cyclohexylphenol, formation of 613 Cyclopentadiene 5-carboxyUc acid 1057 Cyclopropanation, asymmetric 697 Cytochrome P-450 linked microsomal Papaver enzyme 1216 Cytotoxicity 654 CZE 971-974... 

Strongly electron-deficient aryl halides react with alcohols without any catalyst. Catalyzed reaction is sometimes better than uncatalyzed reaction as shown by the reaction of 4-bromo-2-chlorobenzonitrile (25) with cyclohexanol. The ether 26 was obtained in 80 % yield using Pd(0)-VI-9 as a catalyst. On the other hand, the uncatalyzed reaction gave equal amounts of 26 and 27 [7]. 

Panels c—e in Figure 137 show a graphic summary that illustrates how the absolute configuration of an a-chiral carboxylic acid can be deduced from the signs of the A values obtained from its esters with the two enantiomers of any tra/75-2-aryl-l-cyclohexanol. 

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