| Abstract: | Lithiated diethyl prop-2-enylphosphonate adds to an aliphatic or an aromatic aldehyde, yielding a diastereomeric mixture of the kinetically controlled α-adduct. Upon warming, these adducts decompose back to starting materials to give finally the thermodynamically controlled γ-adducts, or undergo fragmentation to diethyl phosphate and (E) dienes. The distribution of the first product between these two pathways is a function of the aldehyde (aromatic vs. aliphatic) and of steric interactions operating within the two diastereomers of the adduct. |
