Synthesis and reactions of alpha-keto-beta-hydroxyphosphonates

Barış, Şehriban
This thesis presents synthesis and different reactions of alpha-keto-beta-hydroxyphosphonates. Toward this aim, the hydroxyl functionality of alpha-hydroxycarboxylic acids were protected with alkyl or acyl groups and then formation of acid chloride followed by the reaction with trialkylphosphite furnished protected alpha-keto-beta-hydroxyphosponates. Nucleophilic addition reactions were applied to these compounds to obtain quaternary alcohols with phosphonate functionality. The addition reactions were tried with organocatalysts for the enantioselective formation of desired products.


Development of acyl anion precursors and their applications
Reis, Ömer; Demir, Ayhan Sıtkı; Department of Chemistry (2005)
This thesis presents the development of new acyl anion precursors and their applications. The main concern of this thesis was to make use of acyl anion precursors in catalytic bond forming reactions. Toward this aim, previously known cyanide ion catalyzed cleavage of benzils was investigated in scope and efficiency in unsymmetrical benzoin condensation. Although benzils were proved to be useful entities as acyl anion precursors in benzoin condensation, they suffer some major drawbacks. Therefore acylphospho...
Synthesis and enzymatic resolution of various cyclopentenoid and cyclohexenoid type compounds
İyigün, Çiğdem; Tanyeli, Cihangir; Department of Chemistry (2005)
The aim of this thesis is to synthesize enantiomerically enriched cyclopentenoid and cyclohexenoid type of compounds with quaternary carbon stereocenters that are the simplest precursors of the complex natural products. The first part of the study involves the preparation of ?'-acetoxy ?'-substituted ?,β-unsaturated cyclic ketones. Methylation, ethylation, benzylation and allylation of cyclohexenone and cyclopentenone derivatives are performed. Then, these compounds are regioselectively oxidized at the ?'-p...
Self condensation reaction of alpha-ketophosphonates
Göllü, Mehmet; Demir, Ayhan Sıtkı; Department of Chemistry (2007)
This thesis presents synthesis of tertiary α-hydroxy phosphonate derivatives. α-Ketophosphonates is known that they are both acyl anion precursors and electrophiles. In this work, α-ketophosphonates were used as both acyl anion precursors and electrophiles in the presence of catalytic amount of KCN. α-Ketophosphonates underwent benzoin-type condensation reaction.
Synthesis of 3-[(4-Nitrophenyl)thio]-Substituted 4-Methylene-1-pyrrolines from N-Propargylic beta-Enaminones
Korkmaz, Esra; Zora, Metin (American Chemical Society (ACS), 2020-04-03)
A facile and efficient method for the synthesis of 3-[(4-nitrophenyl)thio]-substituted 4-methylene-1-pyrrolines is described. When treated with 4-nitrobenzenesulfenyl chloride in refluxing acetonitrile, N-propargylic beta-enaminones produced alpha-sulfenylated N-propargylic beta-enaminones, which, in the presence of sodium hydride or cesium carbonate, underwent nucleophilic cyclization to afford 4-methylene-3-[(4-nitrophenyl)thio]-1-pyrrolines in good to high yields. It was shown for the first time that on ...
Addition of trifluoromethyltrimethylsilane to acyl phosphonates: Synthesis of TMS-Protected 1-alkyl-1-trifluoromethyl-1-hydroxyphosphonates and 1-aryldifluoroethenyl phosphates
Demir, Ayhan Sıtkı; Eymur, Serkan (American Chemical Society (ACS), 2007-10-26)
Addition reactions of nucleophilic CF3TMS to acyl phosphonates were investigated. Various acyl phosphonates reacted readily with CF3TMS in the presence of K2CO3 in DMF at rt to give 1-alkyl-2,2,2-trifluoro-1-trimethylsilyloxyethylphosphonate in 70−90% yields. When benzoyl phosphonates were used as starting material, after addition of CF3, the formed alcoholate undergoes phosphonate−phosphate rearrangement to form the acyl anion, followed by elimination of F- to give 1-aryldifluoroethenyl phosphates in 87−97...
Citation Formats
Ş. Barış, “Synthesis and reactions of alpha-keto-beta-hydroxyphosphonates,” M.S. - Master of Science, Middle East Technical University, 2007.