Kinetic study on the epimerization of trityloxymethyl butyrolactol by liquid chromatography

Determination of Ethofumesate‐2‐hydroxy Stereolability by Dynamic HPLC

“…This indicates that there is a TFA and DEA concentration region in which enantiomerization kinetics is lowered as previously reported by Li et al. (2004) for trityloxymethyl butyrolactol, a chiral hemiacetal. The results corroborate with the ΔS # value determined and showed that ETO‐OH enantiomerization kinetics is catalyzed by acid and base.…”

Configurational analysis of cubebins and bicubebin from Aristolochia lagesiana and Aristolochia pubescens

“…This phenomenon has been observed, for example, in carbohydrates (Pihlaja and Kleinpeter, 1994), trityloxymethyl butyrolactols (Li et al, 2004), and butyrolactol lignans (Wei-Ming et al, 1987). Therefore, dynamic molecular processes were investigated using NMR techniques.…”

Stereolabile chiral compounds: analysis by dynamic chromatography and stopped-flow methods

“…17, 18 Li and co-workers were able to determine the diastereomerization barrier of stereolabile trityloxymethyl butyrolactol using an achiral C 18 -column under reversed phase conditions. 19 The atropisomerization of a series of axially chiral biaryl derivatives of 4-(dimethylamino)pyridine, DMAP, has been investigated by Spivey et al using Chiralcel OB, OD, OJ or Chiralpak AD as the CSP in order to identify conformationally stable, DMAP-derived catalyst candidates for effective kinetic resolution of secondary alcohols. 20 Wolf and Tumambac investigated the isomerization of 1,8bis(29-phenyl-49-pyridyl)naphthalene over a temperature range of more than 100 uC using dynamic HPLC and computer Rotation of either pyridyl ring of 1,8-bis(29-phenyl-49-pyridyl)naphthalene about the pyridyl-naphthalene bond results in interconversion between the meso syn-and the two axially chiral anti-isomers (Fig.…”