Resolution Approaches Toward Enantiopure Planar Chiral 7‐bromo‐4‐hydroxy [2.2]paracyclophane
Abstract
The resolution of racemic planar chiral 7‐bromo‐4‐hydroxy [2.2]paracyclophane was first achieved through the formation of epimeric esters derived from N ‐phtalimide L ‐isoleucine. Two successive crystallization steps, followed by saponification, enabled the isolation of the ( R P ) enantiomer in enantiopure form (ee > 99%) and in 33% overall yield. In contrast, the opposite ( S P ) enantiomer could only be obtained with a moderate enantiomeric excess of 46%. To overcome this limitation, an alternative strategy based on an early‐stage resolution process was developed. This method relied on the separation of the two enantiomers of racemic 4‐hydroxy [2.2]paracyclophane by high‐performance liquid chromatography with a Daicel Chiralpack IA column, followed by regioselective bromination. This sequence produced both enantiomers of the targeted disubstituted [2.2]paracyclophane, which were isolated in pure enantiomeric form and obtained in good overall yields.
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BibTeX
@article{coz2026resolution,
title = {{Resolution Approaches Toward Enantiopure Planar Chiral 7‐bromo‐4‐hydroxy [2.2]paracyclophane}},
author = {Arthur Le Coz and Thomas Desclais and Fabien Le Cavelier and Jean‐françois Lohier and Cyprien Lemouchi and Stéphane Perrio},
journal = {European Journal of Organic Chemistry},
year = {2026},
month = sep,
doi = {10.1002/ejoc.70814},
url = {https://normandie-univ.hal.science/hal-05744288v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Resolution Approaches Toward Enantiopure Planar Chiral 7‐bromo‐4‐hydroxy [2.2]paracyclophane
AU - Arthur Le Coz
AU - Thomas Desclais
AU - Fabien Le Cavelier
AU - Jean‐françois Lohier
AU - Cyprien Lemouchi
AU - Stéphane Perrio
PY - 2026
DA - 2026/09/09
JO - European Journal of Organic Chemistry
DO - 10.1002/ejoc.70814
UR - https://normandie-univ.hal.science/hal-05744288v1
AB - The resolution of racemic planar chiral 7‐bromo‐4‐hydroxy [2.2]paracyclophane was first achieved through the formation of epimeric esters derived from N ‐phtalimide L ‐isoleucine. Two successive crystallization steps, followed by saponification, enabled the isolation of the ( R P ) enantiomer in enantiopure form (ee > 99%) and in 33% overall yield. In contrast, the opposite ( S P ) enantiomer could only be obtained with a moderate enantiomeric excess of 46%. To overcome this limitation, an alternative strategy based on an early‐stage resolution process was developed. This method relied on the separation of the two enantiomers of racemic 4‐hydroxy [2.2]paracyclophane by high‐performance liquid chromatography with a Daicel Chiralpack IA column, followed by regioselective bromination. This sequence produced both enantiomers of the targeted disubstituted [2.2]paracyclophane, which were isolated in pure enantiomeric form and obtained in good overall yields.
SN - 1434-193X
SN - 1099-0690
ER -