REACTION OF LITHIUM DERIVATIVE OF DIETHYL PHENYLMETHANE-PHOSPHONATE WITH KETONES |
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Authors: | Jordanka Petrova Nikolai G Vassilev Marko Kirilov |
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Institution: | Faculty of Chemistry , University of Sofia , 1 Anton Ivanov Av., 1126 , Sofia , Bulgaria |
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Abstract: | Abstract The reaction of the lithium derivative of diethyl ester of phenylmethanephosphonic acid (1-Li) with alkanones, cycloalkanones, alkylaryl and diarylketones 2s-b is studied at -70°C in THF. The corresponding adducts-diethyl esters of l-phenyl-2,2-dialkyl(phenyl)-2-hydroxyethanephosphonic acids 3s-h are isolated, their yields being usually higher at short reaction time. The olefination of 3-Li as well as of 3 (both by thermolysis or in acidic media) proceeds in low degree, while in the case of 3-Na the yields of alkenes 4 are good. The relative configurations of 3b. 31 and 3g are determined by IR and NMR-spectra, as well as by their stereospecific olefination. “Threo”-stereoselectivity of the addition stage of the reaction of 1-Li with 2b, 21 and 2g is observed, the “threo”/“erythro” ratio remaining independent on the reaction time. |
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Keywords: | Benzylphosphonate carbanion reaction with ketones threo/erythro ratio 2- hydroxyethanephosphonates |
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