The CP Molecule Labyrinth: A Paradigm of How Endeavors in Total Synthesis Lead to Discoveries and Inventions in Organic Synthesis

Graphical Abstract

Total synthesis programs directed toward complex molecules may take the form of unrelentless campaigns in which the synthetic chemist is faced with unprecedented challenges and unforeseen obstacles, but which often lead to invaluable fundamental knowledge and powerful new technologies. Here the authors describe one of the most arduous and rewarding endeavors in total synthesis of modern times—the synthesis of the CP molecules (see scheme)—and compare it to the Greek mythology's Labyrinth and the conquest of the Minotaur by Theseus.

Abstract

Imagine an artist carving a sculpture from a marble slab and finding gold nuggets in the process. This thought is not a far-fetched description of the work of a synthetic chemist pursuing the total synthesis of a natural product. At the end of the day, he or she will be judged by the artistry of the final work and the weight of the gold discovered in the process. However, as colorful as this description of total synthesis may be, it does not entirely capture the essence of the endeavor, for there is much more to be told, especially with regard to the contrast of frustrating failures and exhilarating moments of discovery. To fully appreciate the often Herculean nature of the task and the rewards that accompany it, one must sense the details of the enterprise behind the scenes. A more vivid description of total synthesis as a struggle against a tough opponent is perhaps appropriate to dramatize these elements of the experience. In this article we describe one such endeavor of total synthesis which, in addition to reaching the target molecule, resulted in a wealth of new synthetic strategies and technologies for chemical synthesis. The total synthesis of the CP molecules is compared to Theseus' most celebrated athlos (Greek for exploit, accomplishment): the conquest of the dreaded Minotaur, which he accomplished through brilliance, skill, and bravery having traversed the famous labyrinth with the help of Ariadne. This story from Greek mythology comes alive in modern synthetic expeditions toward natural products as exemplified by the total synthesis of the CP molecules which serve as a paradigm for modern total synthesis endeavors, where the objectives are discovery and invention in the broader sense of organic synthesis.