89630-27-3Relevant academic research and scientific papers
Role of Solvent on the Diastereoselectivity of Oxazolidine Formation from (-)-Ephedrine
Agami, Claude,Rizk, Toufic
, p. 1485 - 1486 (1983)
Under kinetic control, the stereochemical course of the condensation between (-)-ephedrine and p-cyano- or p-nitro-benzaldehyde is solvent dependent; no noticeable stereoselectivity was observed in chloroform whereas diastereo-differentiation occurred in methanol.
STEREOCHEMISTRY-60 KINETIC CONTROL OF ASYMMETRIC INDUCTION DURING OXAZOLIDINE FORMATION FROM (-)-EPHEDRINE AND AROMATIC ALDEHYDES
Agami, Claude,Rizk, Toufic
, p. 537 - 540 (2007/10/02)
Kinetically controlled oxazolidine formation was observed with aromatic aldehydes substituted by electron-withdrawing groups.The stereoselectivity is solvent dependent: non-stereoselective ring closure occurred in chloroform while a high diastereodifferentiation was observed in methanol.The first oxazolidine showing an unambiguous 2R configuration was synthesized from p-bromobenzaldehyde and (-)-ephedrine in alcohol medium.A mechanism involving a nucleophilic assistance by alcoholic solvents is suggested in order to clarify the differences in stereoselectivity.
