Trennung der Enantiomere von 2,2′‐Dihydroxy‐1,1′‐binaphthyl und 10,10′‐Dihydroxy‐9,9′‐biphenanthryl durch Komplexierung mit N‐Alkyl‐cinchonidiniumhalogeniden

Abstract

a C6 C Abb. 1. Molekulstruktur von 1 dim Kristall (Modell B). Die Schwingungsellipsoide reprlsentieren 50 % Aufenthaltswahrscheinlichkeit der Elektronen, ge-

2,8′-Disubstituted-1,1′-Binaphthyls: A New Pattern in Chiral Ligands

“…Thus, tosylate 31 is known to produce the tetrahydropyrane derivative 32 in alkaline medium rather than the expected eight-membered crown ether (Scheme 9). Preparative resolution has been achieved for hydroxy bromide (AE)-22 (vide infra), [52,53] from which enantiopure 18, 25, and 26 were synthesized (vide infra). [44] Chem.…”

“…Its single co-crystallization with N-benzylcinchonidinium chloride in acetonitrile [52,53] afforded a crystalline inclusion complex that contained ()-22 (99.4 % ee), while the mother liquor was enriched in the (À)-enantiomer (84 % ee). Its single co-crystallization with N-benzylcinchonidinium chloride in acetonitrile [52,53] afforded a crystalline inclusion complex that contained ()-22 (99.4 % ee), while the mother liquor was enriched in the (À)-enantiomer (84 % ee).…”

Synthesis of Enantiomerically Pure Dissymmetric 2,2'‐Disubstituted9,9'‐Spirobifluorenes

“…Since we had had some good experiences with resolution procedures based on clathrate formation, [16,17] we were especially interested in evaluating this approach. Unfortunately, all our attempts to obtain clathrate formation with cinchonidine derivatives or tartaric acid derivatives proved unsuccessful.…”