Chirality is Just Turtles All the Way Down

L-DOPA is the best drug we have for Parkinson’s disease. If you take L-DOPA and reflect it in a mirror, you get a different molecule: D-DOPA, which does absolutely nothing for Parkinson’s and causes potentially deadly side effects. Making just L-DOPA without D-DOPA is surprisingly hard – so hard that the person who finally figured out how to do it won the 2001 Nobel Prize in Chemistry.