cyclized by LHMDS to give 5,5-disubstituted (S)-4-amino-2(5H)-furanones (S)-4 and (S)-5. Different substituents (H. Me, OBn, OH) in the 3-position of the furanones were introduced by selecting the appropriate acylating agent, which in the case of benzyloxyacetyl chloride led to the novel structure type of 4-amino-3-hydroxyfuranones (S)-5. For the synthesis of 5,5-disubstituted (S)-tetronic acids (S)-8, ketone
Absolute Configuration of Ketone Cyanohydrins by <sup>1</sup>H NMR: The Special Case of Polar Substituted Tertiary Alcohols
作者:Iria Louzao、Rosa García、José Manuel Seco、Ricardo Riguera
DOI:10.1021/ol8023314
日期:2009.1.1
The absolute configuration of ketone cyanohydrins can be assigned from analysis of the 1H NMR spectra of the corresponding (R)- and (S)-MPA ester derivatives and use of ΔδRS signs. This is an application of the NMR methodology for stereochemical assignment to tertiary alcohols possessing polar groups as substituents.
酮氰醇的绝对构型可以从分析被分配1个相应的(的1 H NMR谱- [R和( - )小号)-MPA酯衍生物和使用Δδ RS迹象。这是NMR方法在立体化学上分配给具有极性基团作为取代基的叔醇的应用。