Organic chemistry underwent profound changes in the second half of the twentieth century, and one of the scientists responsible for these advances is Donald J. Cram. When he entered the profession in the 1940s, organic chemistry was primarily concerned with elucidating molecular structure and with synthesizing new molecules by mixing reagents with organic compounds by a method that was more or less ad hoc. The mechanisms of reactions were infrequently exploited in directing reactions towards a desired product. In the years after World War II reaction mechanisms attracted new attention; the exact three-dimensional details of how molecules combine to form products became known, and chemists realized that compounds of very specific shapes could be constructed. This was called stereochemistry, and it had valuable applications for the discipline of making molecules that make other molecules--that is, building compounds that can hold other compounds in a specific configuration, which in...