A team of chemists recently noted that the database of the Beilstein Information System, containing over 9.6 million organic compounds, includes significantly more substances with an even number of carbon atoms than with an odd number. Statistical analyses of smaller sets of organic compounds, such as the Cambridge Crystallographic Database or the CRC Handbook of Chemistry and Physics, led to the same results. A possible explanation for the observed asymmetry might be that organic compounds are ultimately derived from biological sources, and nature frequently utilized acetate, a C2 building block, in its syntheses of organic compounds. It may therefore be that the manufacturers’ and synthetic chemists’ preferential use of relatively economical starting materials derived from natural sources has left permanent traces in chemical publications and databases.
