On the Relationship between Classical Structure Determination and Retrosynthetic Analysis/Total Synthesis†

The relationship between classical structure determination and retrosynthetic analysis combined with total synthesis is examined in detail. The chemical degradation steps in the former are the counterparts of the retrosynthetic steps in the latter. And the gedankenexperiment, also known as “paper chemistry,” working forward and solving the structure from the degradation data, is the counterpart of the experimental forward steps in a total synthesis. The wide use of genealogic‐like “trees” to organize and illustrate many reaction sets in organic chemistry is discussed. Excerpts from the writings of Sir Robert Robinson, R. B. Woodward, and Carl Djerassi reveal historically important insights about these activities in the 1940s–1960s.