403670-51-9Relevant academic research and scientific papers
Preparation of enantiopure butane-2,3-diacetals of glycolic acid and alkylation reactions leading to α-hydroxyacid and amide derivatives
Ley, Steven V.,Diez, Elena,Dixon, Darren J.,Guy, Richard T.,Michel, Patrick,Nattrass, Gillian L.,Sheppard, Tom D.
, p. 3608 - 3617 (2007/10/03)
The preparation of butane-2,3-diacetal protected glycolic acid and related systems is described together with highly selective alkylation reactions of (R,R) and (S,S) butanediacetal protected glycolic acid. These compounds are readily deprotected to give
Palladium-Catalyzed Arylation of Trimethylsilyl Enolates of Esters and Imides. High Functional Group Tolerance and Stereoselective Synthesis of α-Aryl Carboxylic Acid Derivatives
Liu, Xiaoxiang,Hartwig, John F.
, p. 5182 - 5191 (2007/10/03)
A general procedure for the palladium-catalyzed arylation of trimethylsilyl enolates of esters and imides is reported. In the presence of ZnF2 or Zn(O-t-Bu)2 as an additive, the trimethylsilyl enolates of esters, including those bearing α-alkoxy derivatives, underwent arylation in high yield with high functional group tolerance. This arylation chemistry was extended to ester derivatives bearing chiral auxiliaries to form new tertiary stereocenters. The arylation of imides bearing the Evans auxiliary proceeded with selectivities up to 90% de. Further, the arylation of the ketal developed by Ley provided α-aryl glycolates with excellent diastereoselectivities (90 to >98% de). This reaction provides a convenient route to the synthesis of enantiopure α-aryl-α-hydroxy esters. Reactions conducted with Zn(O-t-Bu)2 as an additive occurred at room temperature to give enhanced diastereoselectivities with both chiral reagents. Mechanistic studies showed that the reaction conditions are neutral enough that the observed diastereomeric ratios reflect kinetic selectivities.
A new route to butane-1,2-diacetals and the development of alternative substitution patterns to facilitate differential protection of the products
Ley,Michel
, p. 1793 - 1795 (2007/10/03)
The utility of 2,3-dialkoxybutan-1,3-dienes as reagents for the protection of vicinal diols and α-hydroxy acids as their corresponding 1,2-diacetals is demonstrated together with their later deprotection under mild reaction conditions.
