The Principle of Minimum Chemical Distance (PMCD)

The principle of minimum chemical distance (PMCD) allows one to formulate the isoprene rule, the conversion of tetrahydrodicyclopentadiene into adamantane, five syntheses of colchicine, and the syntheses of C 16 ‐hexaquinacene, morphine and strychnine as optimization problems which can be solved by computers in less than a second. The principle of minimum chemical distance is based on an algebraic theory of constitutional chemistry. The PMCD, a corollary to the well known principle of minimum structure change, is a quantitative heuristic rule which serves as the foundation of the computer‐assisted combinatorial solution of a great variety of chemical problems, particularly in substructure analysis, the study of reaction mechanism, and the design of syntheses.