92605-40-8Relevant academic research and scientific papers
Structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid (+/-)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid
Angelova, O.,Macicek, J.,Vassilev, N. G.,Momchilova, S.,Petrova, J.
, p. 253 - 258 (2007/10/02)
The crystal structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid (1) and of (+/-)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid (2) have been solved by X-ray methods.They are built up in a similar way to centrosymmetric dimers of hydrogen-bonded molecules.The orientation of the substituents around the central C-C bond in both molecules fulfills the requirement for the least spatial hindrance.The observed shift of the vOH stretching frequencies from 3312(1), 3346(2) cm-1 in solid to 3408(1), 3450(2), in diluted (10-3 M) tetrachloromethane solution, indicates the formation of intramolecular hydrogenbonded species.
STEREOSELECTIVITY OF THE WITTIG-HORNER REACTION WITH BENZYLPHOSPHONATE CARBANIONS AND ALDEHYDES
Petrova, Jordanka,Momchilova, Snejana,Vassilev, Nikolay G.
, p. 45 - 52 (2007/10/02)
The interaction of Li-diethylbenzylphosphonate 1-Li with aldehydes 2 is studied at different reaction conditions, the corresponding β-hydroxyethanephosphonate 3 being isolated.It is found that in these cases the aldol stage of the HWE reaction is not stereoselective or threo isomers predominate.The elimination stage leads only to trans-alkene due to the electron and steric influence of the substituents at the phosphorus atom. Key words: Stereoselectivity; benzylphosphonate carbanion; reaction with aldehydes; threo/erythro ratio; 2-hydroxyphosphonates.
La reaction de Wittig-Horner a partir de phosphonate benzylique permet-elle la synthese de stilbene cis ?
Bottin-Strzalko, Tekla,Seyden-Penne, Jacqueline
, p. 161 - 163 (2007/10/02)
The reaction of benzylic phosphonate 2 (Ar = Ph, R = Et) with benzaldehyde gives only trans stilbene whatever the reaction conditions.The base induced decomposition of the two diastereoisomeric hydroxyphosphonates 4 and 5 (Ar = Ar' = Ph, R = Et) precursors of trans or cis stilbene shows that only the former leads to the corresponding olefin; the latter never gives the cis isomer.
