The enterprise of synthesis: from concept to practice.

A retrospective account of natural products synthesis adopting the Chiral Synthon (Chiron) Approach and spanning nearly 50 years of personal research activity is presented highlighting the interplay between the eye and the mind's eye. Synthesis planning is discussed in terms of visual relational and visual reflexive thinking modalities relying on the recognition of naturally occurring nonracemic starting materials such as amino acids, carbohydrates, hydroxy acids, and terpenes in the carbon framework of target molecules. Lessons learned and synthetic methods developed are discussed in the context of selected natural products covered in this Perspective.