The hypothesis that, when a @[email protected] leading to an @[email protected] @[email protected] (or product) has nearly the same energy as that intermediate, the two are interconverted with only a small reorganization of molecular structure. Essentially the same idea is sometimes referred to as 'Leffler's assumption', namely, that the @[email protected] bears the greater resemblance to the less @[email protected] species (reactant or @[email protected]/product). Many text books and physical organic chemists, however, express the idea in Leffler's form, but attribute it to Hammond. As a corollary, it follows that a factor stabilizing a @[email protected] will also stabilize the @[email protected] leading to that intermediate. The acronym 'Bemahapothle' (Bell, Marcus, Hammond, Polanyi, Thornton, Leffler) is sometimes used in recognition of the principal contributors towards expansion of the original idea of the Hammond postulate.
See also:
More O'Ferrall–Jencks diagram
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1119 [Terms] [Paper]