Organic Chemistry in "Real Life"
We are finally starting to talk about reactions of organic molecules. Organic reactions convert one organic molecule into another one by breaking and making bonds. As you are learning in lab, a series of organic reactions that transform a simple organic molecule into a more complex one is called synthesis of the more complex structure. Synthesis can involve only one reaction, as we do in first semester organic lab, or it can involve a series of reactions, as we will do in lab next semester.
Synthesis of organic molecules is one of the main tasks of organic chemists. Believe it or not, there really is a joy in watching crystals grow of a molecule that nobody has ever made before. You hold the only example of that particular organic structure that exists in the world!
Organic synthesis may be said to have started around the turn of the 19th century in Germany, where chemists sought ways to make dyes other than those obtained from plants. Dyes were very important commercially at the time, and remain so to this day. An obvious example for me is in the area of photography (I used to work at the Eastman Kodak Company). Chemists at Kodak synthesized over 30,000 organic dyes for various uses in photographic film paper, filters etc. Dyes are also synthesized, for example, to satisfy the desire of my daughter to change her hair to any color she likes! This blue was from several years ago when she was about 13. After that her hair was re-dyed so many times that we had both just about forgotten what her natural hair color was. Now that she is grown and SHE has to pay to dye her hair, her natural hair color has finally reappeared, I wonder why......?
Chemists have synthesized some extraordinarily complex molecules. The synthesis of Vitamin B12 in 1972 (structure below) took 11 years, required more than 90 chemical reaction steps and involved over 100 people.
Some more recent examples of complex syntheses are taxol, brevitoxin and ionomycin. Remember, not only were these complex structures assembled from very small constituent parts, the stereochemistry at EACH center had to be maintained! Why are these very complex compounds synthesized? Usually for drug purposes. Taxol, for example, is apparently a promising anti-tumor agent, but can only be isolated in microscopic quantities from its natural source, the bark of the relatively rare and slow-growing pacific yew tree.
It has been claimed that chemists can now synthesize ANY structure that might be proposed, and that synthesis is a dead research area. I do not agree. Syntheses of compounds such as those shown here require extraordinary commitment of manpower, better and more efficient synthetic methods will always be required!