Ones function

The remainder of the input file gives the basis set. The line, 1 0, specifies the atom center 1 (the only atom in this case) and is terminated by 0. The next line contains a shell type, S for the Is orbital, tells the system that there is 1 primitive Gaussian, and gives the scale factor as 1.0 (unsealed). The next line gives Y = 0.282942 for the Gaussian function and a contiaction coefficient. This is the value of Y, the Gaussian exponential parameter that we found in Computer Project 6-1, Part B. [The precise value for y comes from the closed solution for this problem S/Oir (McWeeny, 1979).] There is only one function, so the contiaction coefficient is 1.0. The line of asterisks tells the system that the input is complete. 

FGI Functional Group Interconversion The operation of writing one functional group for another so that disconnection becomes possible. Again the reverse of a chemical reaction. Symbol with FGI written over it. 

Analysis The one functional group is something of a red herring since we shall put in the acetyl side chain by a Friedel-Crafts reaction on the real target molecule, 399A ... 

Group additivity methods must be derived as a consistent set. It is not correct to combine fragments from different group additivity techniques, even for the same property. This additivity approximation essentially ignores effects due to the location of one functional group relative to another. Some of these methods have a series of corrections for various classes of compounds to correct for this. Other methods use some sort of topological description. 

If the target molecule is polyfunctional the synthons must contain more than one functional group. 

Before we start with a systematic discussion of the syntheses of difunctional molecules, we have to point out a formal difficulty. A carbonmultiple bond is, of course, considered as one functional group. With these groups, however, it is not clear, which of the two carbon atoms has to be named as the functional one. A 1,3-diene, for example, could be considered as a 1,2-, 1,3-, or 1,4-difunctional compound. An a, -unsaturated ketone has a 1.2- as well as a 1,3-difunctional structure. We adhere to useful, although arbitrary conventions. Dienes and polyenes are separated out as a special case. a, -Unsaturated alcohols, ketones, etc. are considered as 1,3-difunctional. We call a carbon compound 1,2-difunctional only, if two neighbouring carbon atoms bear hetero atoms. 

Various butadiene telomers obtained by Pd-calalyzed reactions have one functional group at one end and a terminal and an internal double bond, and they... 

Table 111-103 2-Alkylthiazoles with one function on the alkyl group Table 111-104 4-Alkylthiazoles with one function on the alkyl group Table I1I-105 5-Alkylthiazoles with one function on the alkyl group...

TABLE nM03, 2-ALKYLTHlAZOLES WITH ONE FUNCTION ON THE ALKYI. GROUP... 

Many compounds contain more than one functional group Prostaglandin Ei a hormone that regulates the relaxation of smooth muscles con tains two different kinds of carbonyl groups Classify each one (aldehyde ketone carboxylic acid ester amide acyl chloride or acid anhydride) Identify the most acidic proton in prostaglandin Ei and use Table 1 7 to estimate its pK ... 

Prostaglandins arise from unsaturated C20 carboxylic acids such as arachidonic acid (see Table 26 1) Mammals cannot biosynthesize arachidonic acid directly They obtain Imoleic acid (Table 26 1) from vegetable oils m their diet and extend the car bon chain of Imoleic acid from 18 to 20 carbons while introducing two more double bonds Lmoleic acid is said to be an essential fatty acid, forming part of the dietary requirement of mammals Animals fed on diets that are deficient m Imoleic acid grow poorly and suffer a number of other disorders some of which are reversed on feed mg them vegetable oils rich m Imoleic acid and other polyunsaturated fatty acids One function of these substances is to provide the raw materials for prostaglandin biosynthesis... 

In this case there is one functional group of each kind per molecule, and each could titrated as a double check of the method. 

Filtration. Here the prime function is to retain sod or other fine materials, whde allowing water to pass through. Again, it is seen that more than one function is being performed (Fig. 6). If there were no drainage of water taking place, movement, and therefore retention of the sod, would not be of concern. 

Acetoiicetyliition Reactions. The best known and commercially most important reaction of diketene is the aceto acetylation of nucleophiles to give derivatives of acetoacetic acid (Fig. 2) (1,5,6). A wide variety of substances with acidic hydrogens can be acetoacetylated. This includes alcohols, amines, phenols, thiols, carboxyHc acids, amides, ureas, thioureas, urethanes, and sulfonamides. Where more than one functional group is present, ring closure often follows aceto acetylation, giving access to a variety of heterocycHc compounds. These reactions often require catalysts in the form of tertiary amines, acids, and mercury salts. Acetoacetate esters and acetoacetamides are the most important industrial intermediates prepared from diketene. 

Function. This describes in a concise, short statement the exact function(s) the component/subsystem must perform. A component/subsystem may have more than one function. 

Nj = number of C-H atomic groups / bonded to at least one functional group or atom in tbe molecule of interest ny= number of different functional groups or atoms in tbe molecule of interest... 

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