Open AccessTosyl esters of cinchonidine and cinchonine alkaloids: the structure–reactivity relationship in the hydrolysis to 9‐epibases
Author(s) -
Karczmarzyk Zbigniew,
Lipińska Teodozja M.,
Wysocki Waldemar,
Denisiuk Monika,
Piechocka Katarzyna
Publication year - 2011
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
eISSN - 1600-5759
pISSN - 0108-2701
DOI - 10.1107/s0108270111027272
Subject(s) - chemistry , tosyl , cinchonidine , cinchonine , van der waals force , hydrogen bond , reactivity (psychology) , diastereomer , hydrolysis , ab initio , stereochemistry , computational chemistry , organic chemistry , molecule , catalysis , enantioselective synthesis , medicine , alternative medicine , pathology
In the crystal structures of the diastereoisomers of O ‐tosylcinchonidine [(9 R )‐cinchon‐9‐yl 4‐methylbenzenesulfonate], (I), and O ‐tosylcinchonine [(9 S )‐cinchon‐9‐yl 4‐methylbenzenesulfonate], (II), both C 26 H 28 N 2 O 3 S, both molecules are in an anti ‐closed conformation and, in each case, the position of the aryl ring of the tosylate system is influenced by an intramolecular C—H...O hydrogen bond. The molecular packing in (I) is influenced by weak intermolecular C—H...O and C—H...π interactions. The crystal structure of (II) features C—H...π interactions and van der Waals forces only. The computational investigations using RHF/6–31G** ab initio and AM1 semi‐empirical methods performed for (I) and (II) and their protonated species show that the conformational and energetic parameters of the molecules are correlated with differences in their reactivity in hydrolysis to the corresponding 9‐epibases.