Abstract Preparation of 1-formyl 1, 1-dialkylmethylphosphonates is described. A carbanionic route is provided by the condensation of α-lithio α, α-disubstituted methylphosphonates with ethylformate whereas a carbocationic route provided by the acid catalyzed rearrangement of β, β-disubstituted epoxyethylphosphonates is re-evaluated.
