R CYCLOALKANES

Cycloalkanes (including X- and R-cycloalkanes and Bi-, Tri-... -cycloalkanes without Steroids)... 

The reagent (I) reacts with /ran.r-cycloalkane-l,2-diols to give a multitude of products. Reaction with c/s-cycloalkane-l,2-diols gives /rans-2-chlorocycloalkyl iicetales in high yield. An example is formulated in equation (I). This reaction... 

A single alkane may have several different names a name may be a common nfflne, or it may be a systematic name developed by a well-defined set of rules. The most widely used system is lUPAC nomenclature. Table 2.6 summarizes the rules for alkanes and cycloalkanes. Table 2.7 gives the r-ules for naming alkyl groups. 

R Stereoisomers (Section 4.2) are compounds whose atoms are connected in the same order but with a different geometry. Among the kinds of stereoisomers we ve seen are enantiomers, diastereomers, and cis-trans isomers (both in alkenes and in cycloalkanes). Actually, cis-trans isomers are just another kind of diastereomers because they are non-mirror-image stereoisomers. 

J. B. Ott and J. R. Goates. "(Solid + Liquid) Phase Equilibria in Binary Mixtures Containing Benzene, a Cycloalkane, an rc-Alkane. or Tetrachloromethane. An equation for Representing (Solid + Liquid) Phase Equilibria", J. Chem. Thermodyn., 15. 267-278 (1983). 

Most of the above-mentioned dihydropyridazinones bear an alkyl substituent either at C-4 or at C-5. However, there are also patents on 4,5-cycloalkane annulated congeners (65, R = substituted Ph X = (CH2)M, n = 1-4) [111, 225, 246-248] and on 6-aryldihydropyridazinones bearing various other substituents at the /J-carbon atoms [206, 211, 229, 237, 249-252]. 

Cycloalkanes R R R H and chelating arenes ArH were oxidatively cross-conpled to Ar R R R by [RuClj(p-cymene)]2/TBHP/135°C (the reactants were the solvent) thus 2-phenylpyridine and cyclo-octane were cross-coupled cf. mech. Ch. 1. Other complexes (Ru(acac)3, [RuCl CCOD)] and RuHj(CO)(PPh3)3) also catalysed the reaction [78]. 

In the group of nonfluorescing alkanes the lifetimes are very short, x < 0.3 nsec an upper limit of i < 3 x 10 sec is estimated. The absence of fluorescence for these compounds may have two causes the low R, i.e., low rate coefficient of the Si Sq radiative transition and the short lifetime, i.e., the very fast chemical decomposition. In the C5 and C7-C10 cycloalkanes the ring strain, which is mainly caused by the repulsive interaction of their unfavorably displaced H atoms, may enhance the rate coefficient of the chemical decay by C-H decompositions. In the excited sates of the geminally branched... 

Review Chapter 5. The inability of atoms in rings to rotate completely about their [Pg.167]

The product consists uf various amounts of high polymer (.r is very large) and discrete cyclosilanes with n = 5-35. This is the largest homologous series of cyclic compounds now known except for the cycloalkanes. Although these compounds are formally saturated, they behave in some ways as aromatic hydrocarbons. They can be reduced to amon ladicals. and EPR spectra indicate that the unpaired electron is delocalized over the entire ring. 06... 

R. A. Alonso, G. D. Vile, R. E. McDevitt, and B. Fraser-Reid, Radical cyclization routes to bridged pyranosides as precursors of densely functionalized cycloalkanes, J. Org. Chem. 57 573 (1992). 

Bond order n and re-character e can be extracted from the properties of p(r) at the bond critical point p (see Table 5). The calculated CC bond order of 1 (n = 1.00), which is obtained from the electron density at the local point p, is not sensitive to the bending of the CC bond as has been pointed out by Cremer and Kraka11. This is in line with the observation made in VB calculations that the overlap between CC hybrid orbitals in 1 is similar to that of other cycloalkanes (see Table 3 and Section V. B)51. 

A salting-out effect occurs for alkanes, cycloalkanes, alkylbenzenes,, R 11 1. 

Hydrocarbons, R—Ha Alkanes CH3CH2CH3 propane Alkenes ch3ch=ch2 propene Alkynes ch3c=ch propyne Cycloalkanes ch2-ch2 /. ch2 ch2 / ch2-ch2 cyclohexane Arenes HC—CH // HC CH / HC CH benzene... 

Compounds of the type RCN have to be called carbonitriles when R is a cycloalkane or similar group ... 

The one-step double functionalization of aromatics—that is, alkylation and acylation—can be accomplished with alkanes or cycloalkanes (in large excess) using the aprotic organic superacids RCO+Al2X7 (R = alkyl, aryl, X = Cl, Br)391 [Eq. (5.152)]. However, the method can be used only for benzene and bromobenzene. 

Because of the chemical inertness of the saturated aliphatic hydrocarbons and of the closely related cycloalkanes, no satisfactory crystalline derivatives can be prepared. A pure sample may be characterised by consideration of such physical properties such as the boiling point, the refractive index (and/or the density), and these physical constants are listed in Table 10.1. If required, confirmation of structure should be sought from a more detailed study of appropriate spectra, particularly 13C-n.m.r., and mass spectra. 

---