β-Hydroxyalkylphosphonates were treated with a weak base such as potassium carbonate in N,N-dimethylformamide to give the corresponding olefins in good yields.
Phosphorohydrazidates have been shown to work as radical precursors by iron-catalyzed aerobic oxidation to generate corresponding phosphonyl radicals. Generated radicals cause intermolecular addition to various alkenes in the presence of molecular oxygen to give beta-hydroxyphosphonate compounds in good yield. (C) 2011 Elsevier Ltd. All rights reserved.
KAWASHIMA, TAKAYUKI;ISHII, TAKAFUMI;INAMOTO, NAOKI, CHEM. LETT., 1983, N 9, 1375-1378
β-Hydroxyalkylphosphonates, which were prepared readily from alkylphosphonates and carbonyl compounds, were treated with a fluoride ion such as CsF or with relatively weak bases such as K2CO3 in N,N-dimethylformamide to give the corresponding olefins in good yields. One molar equivalent of water to bases is effective for increasing the yields of olefins. The stereochemistry of erythro-dimethyl (2-hydroxy-1-methyl-2-phenyl)ethylphosphonate was determined by X-ray crystallographic analysis. Use of threo-isomer gave (E)-olefin exclusively, while that of erythro-enriched isomer afforded predominantly (Z)-olefin, indicating that the present olefination proceeds stereospecifically in a manner of syn-elimination.