Drawing Intermediates

Write a mechanism to show how all three products could be obtained from a common chloronium ion intermediate. Draw structures for the products expected from addition of chlorine to c/s-2-butene in ethanoic acid. Show the configurations, If necessary, review Section 5-5 before working this problem. 

Problem 22.23 in Mechanism 22.8, oniy one Lewis structure is drawn for each intermediate. Draw all other resonance structures for the resonance-stabilized intermediates. 

The behaviour of polymers drawn to low and intermediate draw ratios is similar in many ways to that of isotropic polymers, especially under... 

An explanation for the exceptional reinforcement effect of small amounts of nanoclay -1.5 wt%) at intermediate draw ratios (10 < 20) could be found, if not in micromechani-... 

Write the two major substitution products of the reaction shown below, (a) Write a mechanism to explain the formation of each of them, (b) Monitoring the reaction mixture reveals that an isomer of the starting material is generated as an intermediate. Draw its structure and explain how it is formed. 

SnI reactions proceed via a carbocation intermediate. Draw the carbocation formed on loss of Cl and compare. The more stable the carbocation, the faster the SnI reaction. 

Figure 6. Phase tracing for the trigonal degeneracies. The drawings (which are explained in the caption to Fig. 3) are for intermediate radius q) circling.

Because the intermediates Me and MeiCOH are pretty rmlikely species and they would have to be intermediates in the real reaction too We have already found the first way to recognise a good disconnection it has a reasonable mechanism. Choose a discormection for this molecule, target molecule 3 (TM 3) breaking bond a or b. Draw the arrow and the intermediates. 

Because the acylated product has a delocahsed lone pair and is less reactive than PhNHi. You may have been surprised that LiAlHi reduction completely removes the carbonyl oxygen atom. To help explain this, please draw the likely intermediate. 

Raphael has deyised a commercial synthesis using intermediates 365A and B to provide the two halves of the molecule. B is converted in aqueous add to an isomeric alcohol. Draw this. 

The amide group is readily hydrolyzed to acrylic acid, and this reaction is kinetically faster in base than in acid solutions (5,32,33). However, hydrolysis of N-alkyl derivatives proceeds at slower rates. The presence of an electron-with-drawing group on nitrogen not only facilitates hydrolysis but also affects the polymerization behavior of these derivatives (34,35). With concentrated sulfuric acid, acrylamide forms acrylamide sulfate salt, the intermediate of the former sulfuric acid process for producing acrylamide commercially. Further reaction of the salt with alcohols produces acrylate esters (5). In strongly alkaline anhydrous solutions a potassium salt can be formed by reaction with potassium / /-butoxide in tert-huty alcohol at room temperature (36). 

Oxygen-containing rings can be opened by amines frequently this is followed by reclosure of the intermediate to form a new heterocycle. Thus isoxazoles containing electron-with-drawing substituents give pyrazoles with hydrazine, e.g. (183 Z = O) (183 Z = NH), and... 

The curves in Fig. 15-5 are greatly simplified and only apply to one instant of time. In practice there are always several trams with varying current draw on a stretch of track. Currents and potentials are then subjected to wide time-dependent variations. Without protective measures, the pipe/soil potentials are usually always more negative in the outer regions of a tramway system and more positive in the vicinity of the transformer substation. In a wide intermediate region, potential changes occur in both directions. The current entrance and exit areas can be deter-... 

Some conditions require breaking up the exchanger into multiple parts for the calculations rather than simply using corrected terminal temperatures. For such cases one should always draw the q versus temperature plot to be sure no undesirable pinch points or even intermediate crossovers occur. 

A synthesis of the important biosynthetic intermediate mevalonic acid starts with the enzymatic hydrolysis of the diester A by pig liver esterase. The pro-R group is selectively hydrolyzed. Draw a three-dimensional structure of the product. 

The first step in the addition of an electrophile such as HBr to an alkyne involves protonation and subsequent formation of an intermediate vinyl cation. Where does propyne protonate Compare energies of 1-methylvinyl and 2-methylvinyl cations. Which is more stable Why Measure CC bond distance in the more stable cation. Does the cation incorporate a full triple bond (as in propyne) or a double bond (as in propene). Examine atomic charges and electrostatic potential maps to locate the positive charge in the two cations. Is the more stable ion the one in which the charge is better delocalized Use the charges together with information about the ions geometry to draw Lewis structures (or a series of Lewis structures) for 1-methylvinyl and 2-methylvinyl cations. 

The cleavage reaction occurs in three steps O protonation of the epoxide, Sn2 nucleophilic attack on the protonated epoxide, and deprotonation of the ring-opened product. Draw the complete mechanism. How many intermediates are there Which step determines diol stereochemistry ... 

Draw a Lewis structure (or a series of Lewis structures) for nitrobenzenium ion. Where is the positive charge Examine the electrostatic potential map for nitrobenzenium ion. Where would you expect electron-donor substituents to have the greatest stabilizing effect (consider meta and para positions only) Which is the more stable, meta or para-nitrotoluenium ion (intermediates in nitration of toluene) Compare electrostatic potential maps to that for nitrobenzenium ion. Does your result suggest that methyl acts as an electron donor ... 

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