Most of the time you would attempt building up chirality de novo using chiral auxiliaries, catalysts or reagents as these methods are often more cost-efficient than acquiring a specific chiral reactant — the obvious exception being if a compound exists in the natural chiral pool that you can easily use which is not really the case here.
Example for the classification of C-X-bonds It is important to realize that the bonds 7, 9 and 10 are part of an amide group. These bonds are not classified as amine bonds. Bond 4 is a carboxylic acid single bond, not a bond in an alcohol.
Bonds 3 and 6 are classified as Functional group interconversion retrosynthesis bonds of a carboxylic acid or an amide, respectively, and thus distinguished from a carbonyl bond of an ester. Polycyclic Compounds The method of searching for strategic bonds in polycyclic compounds is only useful for molecules with large condensed ring systems.
A set of topological criteria based on Corey's rules for the treatment of complex ring systems is applied to the query structure. Core bonds are bonds, whose disconnection will lead to the formation of primary rings with more than seven ring atoms.
All this topological criteria are analyzed by WODCA and lead to a rating for strategic bonds in polycyclic compounds. The maximum rating isthe lowest one is a value of 0.
If the user clicks with the left mouse button on the entry Strategic Bonds The Strategic Bonds window is shown in Figure 3. Window for the application of a disconnection strategy Info If you are currently reading the online manual of WODCA you can use the hyperlinks contained in Figure 3.
Just click with the left mouse button on a window element of your interest and follow the link to obtain directly an explanation. Use the back button of your WWW browser to get back to this place. The Strategic Bonds window contains three different window elements, which are now explained in detail.
The left hand area is called strategic bond displaythe right hand area is called disconnection strategy list box and the lower part of the window with the button bar is called action area.
Strategic Bond Display The strategic bond display is used to display a chemical structure that is analyzed for strategic bonds. Context Menu The strategic bond display contains a context menu. The context menu appears after pressing the right mouse button within the strategic bond display.
The context menu is divided into three parts. The upper part is called Precursor Actions. It contains five menu entries which refer to the compound shown in the strategic bond display. This functionality is also offered by the Export menu. The second entry opens a cascaded menu to apply functional group interconversions FGI to the precursor compound see section Functional Group Interconversion.
The third entry allows the application of protective groups PG to the precursor. The fourth command cancels the last modification of the compound shown in the strategic bond display.
Since the tautomerization step is not automatically performed, the user has the choice to work with tautomeric precursors or not.
The scheme in Figure 4 gives an example. The middle part of the context menu is called Strategic Bond Mode and contains three checkbuttons which control the display of strategic bonds in the strategic bond display.
The following two pictures show structures with strategic bonds displayed as Ratings and as Ranks. Note, that only the assignment between Ranks and the corresponding bond is always clear, because it is possible that WODCA rates different bonds with the same value.Retrosynthetic analysis is a technique for solving problems in the planning of organic timberdesignmag.com is achieved by transforming a target molecule into simpler precursor structures without assumptions regarding starting materials.
retrosynthesis by functional group interconversion (fgi) Each functional group has a characteristic reactivity; for example, it might be electron-rich, electron-deficient, acidic, or basic. In order to synthesize organic compounds, we must construct the desired carbon framework while locating the required functional groups in the appropriate.
There are two kinds of steps in retrosynthetic analysis Disconnections – which involves breaking a bond to carbon, or a reverse operation to Functional Group Interconversion (FGI), where functional group is converted to another before the precursor is obtained.
6. Functional Group Interconversion Sky and Water I Maurits Cornelis Escher, Dr. Pere Romea Department of Organic Chemistry Organic Synthesis.
Carbon Backbone & Functional Groups The synthesis of an organic compound must pay attention to Functional groups Functional Group Interconversion (FGI). The functional group interconversion (FGI) reactions are among the most common synthetic processes.
In this experiment, the conversion of cinnamic aldehyde is performed by reduction with LiALH 4 into two different products, depending upon the order of addition of reactants. Functional Group Interconversion (FGI): the process of converting one functional group into another by substitution, addition, elimination, reduction, or oxidation.