Substitution and Rearrangement

In both cases studied using G 56-adamantanes as starting materials rearranged products were observed where oxonium ions occurred as intermediates, namely on treatment of 4°l l,8°l l-diiodo-2,6-dioxa-adamantane (J 2.1.2.1.) and N(6)-phenylsulfonyl-4N(6)8N(S),diiodo.2 -oxa-6-aza-adamantane (47 2.1.5.2.) with silver acetate in acetic acid, see G 36 - G 38 (oxonium ion) - G 39 (adamantane) + G 40 (isotwistane)  

To obtain an equal turnover,the following reaction conditions had to be applied 16 hrs at 95° with the 2,6-dioxa-adamantane J and 230 hrs at 70-75° with the 2-oxa - 

6-aza-adamantane 47. The product distributions are listed in Table 2. It is remarkable that in no case the intermediate iodo-acetoxy-isotwistanes 242 and 244, resp., could neither be isolated nor even be observed. The subsequent reactions to 2S + 243 and 78 + 245, resp., are obviously faster than the formation of 242 from 5 and 244 from 47. This is in agreement with the result that on the one hand 10° -iodo-2,7-dioxa-isotwistane (725), i.e. a corresponding compound without an acetoxy group at C(4), on treatment with silver acetate in acetic acid shows complete interconversion already at room temperature (see 3.2.3.) and on the other hand that by analogous treatment of the 10 -iodo-2-oxa-7-aza-isotwistane 169 after 3 hrs at 60° already no starting material was left (see 3.2.3.). 

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Substitution and rearrangement leads to the equation for the tower height,... 

Since x2 = 1 — xi, dx2 = —dxi. After substitution and rearranging the equation becomes... 

In Volume 13 reactions of aromatic compounds, excluding homolytic processes due to attack of atoms and radicals (treated in a later volume), are covered. The first chapter on electrophilic substitution (nitration, sulphonation, halogenation, hydrogen exchange, etc.) constitutes the bulk of the text, and in the other two chapters nucleophilic substitution and rearrangement reactions are considered. 

Substitution and rearrangement give an equation with only one dependent variable ... 

In such cases, substitution and rearrangement products are often produced together. For a discussion of rearrangements, see Chapter 18. 

In this and subsequent equations enters as a constant of integration such that [M-] = 0 at t = to. According to Eq. (45), 2kt[M-]s on the right-hand side of Eq. (48) may be replaced by the reciprocal of the steady state lifetime r. Making this substitution and rearranging, we obtain the compact relation... 

Acetoxylation proceeds mostly via the radical cation of the olefin. Aliphatic alkenes, however, undergo allylic substitution and rearrangement predominantly rather than addition [224, 225]. Aryl-substituted alkenes react by addition to vic-disubstituted acetates, in which the dia-stereoselectivity of the product formation indicates a cyclic acetoxonium ion as intermediate [226, 227]. In acenaphthenes, the cis portion of the diacetoxy product is significantly larger in the anodic process than in the chemical ones indicating that some steric shielding through the electrode is involved [228]. 

But the entropy of the reacting species can be calculated using statistical mechanics if the partition functions are known. Making the appropriate substitution and rearranging Eq. (9) we have... 

Equation (35) then becomes after substitution and rearrangement... 

Here V is the total volume and D is the specific volume of the polymer. Substitution and rearrangement yields the final form of the Flory-Rehner model [6],... 

In nickel(III) peptide complexes, there is a strong in-plane field provided by the deprotonated peptide linkages (117, 118). Two axially coordinated water molecules are present in the tetragonally distorted complexes which exchange much more rapidly than for the [14]aneN4 species with a substitution rate of constant >106 M l sec-1 for the formation of the imidazole complex (141). However, except for the terminal peptide group, equatorial substitution is very slow. Substitution and rearrangement (125) reactions of these species reveal acid-... 

The velocity term, v, in Equation Cl.1.2 refers to measured initial velocities. The equation s derivation is based on the assumptions that enzyme concentrations are much less than substrate concentrations ([E]tota [S]) and that, over the course of the assay, the concentration of the enzyme-substrate complex remains essentially constant (the steady-state assumption). The point of this discussion is to show that measured initial velocities are expected to be directly proportional to the amount of active enzyme in reaction mixtures. Equation Cl. 1.5, obtained by substituting and rearranging the equations above, more clearly illustrates this relationship. 

C is correct. There are four main reaction types seen in organic chemistry addition, elimination, substitution and rearrangement. In an addition reaction (A + B - C), two reactants add together to form a single product. One reactant splitting into two products is known as an elimination reaction (A B + C). Substitutions... 

Glycals and their derivatives undergo an extensive set of addition, substitution, and rearrangement reactions,5 7 many of which show good selectivities, and as a consequence are the starting materials for the synthesis of many types of compounds. 

K = 10 32 5. Using the equilibrium expression for the above reaction, substituting AP+ by Equation 2.69, and considering that pH = 14 - pOH, substituting and rearranging the logarithmic equation yields... 

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