Functional groups interconversion

This guideline helps us in the next retrosynthetic step for the ICI-D7114 intermediate. Disconnection (c) gave us a compound with two ethers that might be disconnected further by disconnection (e) or (/). 

Disconnection (e) requires alkylation of a compound that is itself an alkylating agent. Disconnection (/) is much more satisfactory, and leads to a compound that is easily disconnected to 4-hydroxyphenol (pdra-cresol) and 1,2-dibromoethane. Using Guideline 3, we can say that it s best to disconnect the bromoethyl group (J) before the benzyl group because the bromoethyl group is more reactive and more likely to cause problems of chemoselectivity. 

The antihypertensive drug ofornine contains an amide and an amine functional group, and we need to decide which to disconnect first. If we disconnect the secondary amine first (b), we will have chemoselectivity problems constructing the amide in the presence of the resulting NH2 group. 

Yet disconnection (a), on the face of it, seems to pose an even greater problem because we now have to construct an amine in the presence of an acyl chloride However, we shall want to make the acyl chloride from the carboxylic acid, which can then easily be disconnected to 2-aminobenzoic acid (anthranilic acid) and 4-chloropyridine, 

By using an appropriate reagent or series of reagents, almost any functional group can be converted into any other. You should already have a fair grasp of reasonable functional group interconversions, They mostly fall into the categories of oxidations, reductions, and substitutions (Chapters 12, 

Disconnection (e) requires alkylation of a compound that is itself an alkylating agent. Disconnection f is much more satisfactory, and leads to a compound that is easily disconnected to 

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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. 

Have you noticed that the disconnections involving H" are simply redox reactions and do not alter the carbon skeleton of the molecule They are not then reaUy discoimections at all but Functional Group Interconversions or FGI for short. 

Functional group interconversions (FGI) are mainly employed to achieve one of the following synthetic objectives ... 

Antithetical functional group interconversions (FGI), additions (FGA), or removals (FOR) are symbolized by the given abbreviations on the double-lined arrow. 

Syntheses by Functional Group Interconversions (Condensation Reactions)... 

Section 15.1 Functional group interconversions involving alcohols either as reactants or as products aie the focus of this chapter. Alcohols aie commonplace natural products. Table 15.1 summarizes reactions discussed in earlier sections that can be used to prepare alcohols. 

A sequence of straightforward functional group interconversions leads from 17 back to compound 20 via 18 and 19. In the synthetic direction, a base-induced intramolecular Michael addition reaction could create a new six-membered ring and two stereogenic centers. The transformation of intermediate 20 to 19 would likely be stereoselective substrate structural features inherent in 20 should control the stereochemical course of the intramolecular Michael addition reaction. Retrosynthetic disassembly of 20 by cleavage of the indicated bond provides precursors 21 and 22. In the forward sense, acylation of the nitrogen atom in 22 with the acid chloride 21 could afford amide 20. 

Another interesting biooxygenation reaction with alkenes, recently identified, represents an enzymatic equivalent to an ozonolysis. While only studied on nonchiral molecules, so far, this cleavage of an alkene into two aldehydes under scores the diversity of functional group interconversions possible by enzymatic processes [121,122]. 

The synthesis of both haliclamines A (64) and B (65) has been achieved (Scheme 6). The first synthesis of both 64 and 65 [35,36] was a convergent approach starting from the monoprotection and functional group interconversions (FGls) of 1,4-butanediol (66) to the monoprotected iodide (67), which... 

Functional Group Interconversion by Substitution, Including Protection and Deprotection... 

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