Professor Semmelhack grew up in Wisconsin and attended the University of Wisconsin for his undergraduate degree in Chemistry. He then obtained his PhD in organic chemistry from Harvard University in 1967. After a year at Stanford as a postdoctoral fellow, he started his independent work at Cornell in 1968. He developed a research program in organic chemistry, with an emphasis on finding new methods for organic synthesis and the application of those methods in the synthesis of molecules of biological significance. He moved to Princeton in 1978 as Professor of Chemistry, where his research interests have broadened to include more application of organic chemistry toward biological problems. He lives in Princeton with his wife and daughter, and enjoys visits by his two older kids, both Princeton grads and both Rocky alumnae!