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DOI: 10.1055/sos-SD-021-00911

Whitehead, A.; Sieck, S. R.; Mukherjee, S.; Hanson, P. R.Science of Synthesis, (200521909.

While the assembly of acylphosphonates via the Arbuzov reaction represents a rapid approach toward this class of compounds (see Section, the Arbuzov reaction can be problematic for systems containing alternate electrophilic sites (e.g., β,γ-unsaturated acylphosphonates) and cases where the products may be unstable to acid or thermal conditions.[‌2‌] In order to circumvent these problems, methods focusing on the oxidation of generally more stable α-hydroxy phosphonates have been developed. The α-hydroxy phosphonate precursor can be readily derived from the Pudovik reaction of an aldehyde with a trialkyl phosphite. Oxidation procedures have utilized a variety of metal-mediated approaches under various conditions, ranging from both homogeneous/heterogeneous to solvent-free conditions. Nonmetal routes include the ParikhDoering, PfitznerMoffatt, and Swern oxidations.[‌5‌‌7‌] These methods provide milder reaction conditions and avoid the use of excess amounts of toxic metal oxidants. Ongoing research in this area has been spurred by the necessity for reactions requiring less substrate specificity. Common problems encountered include retro-Pudovik reactions, in addition to rearrangements of the α-hydroxy phosphonate precursors.