The Four Big Cs of Organic Structure

Composition

Elements ; Weight Ratios ; Atom Ratios ; Molecular Weights

Lavoisier, Berzelius (1789-1830) Ultimately Avogadro/Cannizzaro on mol wt (1860)

Radicals/Types

Wöhler, Liebig, Dumas (1830-1850)

Constitution

Nature and Sequence of Bonds

Couper, Kekulé, Körner (1857-1870)

Configuration

Stereoisomerism that involves bond breakage

van't Hoff, Fischer (1874-1900)

Conformation

Stereoisomerism that involves single-bond rotation

Paternó, Baeyer, Sachse-Mohr (1869-1918) Finally Barton (1950)