molecule
Retrosynthesis
Learning Outcomes
On completing these problems you should be able to:
 • Devise syntheses of simple targets using the principles of retrosynthetic analysis.
 • Demonstrate a knowledge of synthetically important carbon-carbon bond forming reactions and functional group interconversions.

The synthesis of useful substances is, arguably, the most important activity of chemists.   There is a never-ending demand for new, better, chemical products to sustain and improve our lives, e.g medicines, polymers, dyes, food additives, etc. etc.   To meet that demand, chemists have devised principles that allow them to design synthetic routes for the preparation of just about any 'target' compound.  The principal method for devising synthetic routes was developed by Prof E.J. Corey at Harvard University and is called 'retrosynthetic analysis'.   In retrosynthetic analysis, you start with the target and work backwards, asking yourself "What could this target be prepared from, using a reliable reaction?" to arrive at a 'subtarget'.   Then analyse the subtarget in the same way, and continue in this fashion until you arrive at readily available starting materials.  The process is much more complex that than this brief description suggests; for more details consult textbooks or your course notes.  Many useful resources are freely available on the web; the following links are good starting points.   Wikipedia   A. Parsons, York   A. Cammidge, East Anglia   W. Reusch, Michigan State

Of this page you can practise devising syntheses of relatively simple target molecules using the retrosynthetic analysis strategy.   A wide variety of targets are included, but most contain oxygen functional groups, and relatively few contain other heteroatoms such as nitrogen and sulfur.  The reactions that you can choose from are all polar reactions, no pericyclic or radical reactions are included. Although the set of reactions available is restricted, it includes many of the most synthetically valuable CC bond forming reactions and functional group interconversions.  Stereoselectivity is not included in these problems, except for the control of alkene geometry.


How To Use This Page:   Choose the family of compounds you want to work on, choose an "Easy", "Medium" or "Difficult" problem, and click the "Get Problem" button.   This short video tutorial explains how to use the page.

Choose a category of targets   Click on a name to get help on that family of compounds.
Hydrocarbon targets Aromatic targets Monofunctional targets
Difunctional targets
Choose level of difficulty
Easy
More difficult
The problems and instructions will be shown below.


Choose the CC bond-forming reaction, or functional groups interconversion, that you plan to use from one of the drop-down lists below.   Then click the "Check reaction" button to see if it is an appropriate choice.


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Criteria (help):
Two synthons with matched polarity?  
Connection gives target structure?  
Synthons correct for chosen reaction?  






Criteria (help):
Nucleophile skeleton?  
Nucleophile functionality?  
Electrophile skeleton?  
Electrophile functionality?