Strategy of Synthesis

The modem organic chemist has a variety both of reagents and reactions far beyond those we have looked at here. If you study organic chemistry to a more advanced level you should meet many of them but you will find that the principles of their design and use are the same as those you have learnt in this programme. We have now finished the basic types of disconnection and must look at the strategy of synthesis. 

This section will present successively the different F-labelled reagents, the usual conditions of radiofluorinations and then a critical view of the strategies of synthesis of F-precursors, their derivatives and finally their uses for the preparation of F-radiopharmaceuticals. 

In this section and sections H - K the general principles and strategy of synthesis of the many carbon compounds found in living things will be considered. Since green plants and autotrophic bacteria are able to assemble all of their needed carbon compounds from C02, let us first examine the mechanisms by which this is accomplished. We will also need to ask how some organisms are able to subsist on such simple compounds as methane, formate, or acetate. 

The comparison between the reactions of a carbonyl compound with a phosphorus ylide (Wittig s reagent) on one hand and a sulfur ylide on the other shows clearly the complementarity of these reagents in the strategy of synthesis. 

This strategy of synthesis can be compared with the reaction of either acetylchloropyri-dine, in which the acetyl and chloro groups are o- to each other, or 6>-bromobenzamide treated with anions from acetonaphthone265. 

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