The Preparation of Dimethyl α -Hydroxyphosphonates and the Chemical Shift Non-Equivalence of Their Diastereotopic Methyl Ester Groups
作者:Harry R. Hudson、Ramon O. Yusuf、Ray W. Matthews
DOI:10.1080/10426500701690905
日期:2008.6.9
alkanals, aryl aldehydes (or aryl methyl ketones), furfuraldehyde, and 2- or 3-thiophenecarboxaldehyde, respectively, thus confirming the general utility of this synthetic procedure. The 1H and 13C nmr spectra of the products exhibit characteristic chemical shift non-equivalence of the diastereotopic methyl ester groups, for which a tentative order of non-equivalence is reported and discussed.
An efficient and simple synthesis of α‐hydroxyphosphonates via reaction of aldehydes and ketones with dimethylphosphite in the presence of MgCl2/Et3N base system is reported. The use of readily available and easy to handle reagent MgCl2/Et3N makes this method simple, convenient, and practical.
据报道,在MgCl 2 / Et 3 N碱体系存在下,醛和酮与亚磷酸二甲酯反应可有效,简单地合成α-羟基膦酸酯。使用易于获得且易于处理的试剂MgCl 2 / Et 3 N使该方法简单,方便且实用。
Accurate in situ 31P{1H} assay of enantiopurity in α-hydroxyphosphonate esters using a diazaphospholidine derivatizing agent
作者:Paul G. Devitt、Michael C. Mitchell、John M. Weetman、Roger J. Taylor、Terence P. Kee
DOI:10.1016/0957-4166(95)00265-q
日期:1995.8
A rapid, convenient and efficient in situ assay of enantiomeric excess in alpha-hydroxyphosphonate esters is reported exploiting P-31/H-1} NMR analysis of the diastereoisomers formed upon condensation with a phosphorochloridite reagent containing a chiral diazaphospholidine ring. Use of this chiral framewark affords chemical shift dispersions >5 ppm between diastereoisomers. Accurate integrations are thus possible once account is taken of differential n.O.e. effects and spin lattice T-1 relaxation rimes of the phosphorus nuclei.