Premium
Esters of 1‐ O ‐Demethylthiocolchicines: Formation of Isomers in Chloroform Solution
Author(s) -
Kerekes Peter,
Brossi Arnold,
FlippenAnderson Judith L.,
Chignell Colin F.
Publication year - 1985
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19850680306
Subject(s) - chemistry , chloroform , diacetyl , solid state , stereochemistry , crystallography , medicinal chemistry , organic chemistry
1‐ O ‐Acetyl‐1‐ O ‐demethylcolchicine, and acylated 1‐ O ,2‐ O ‐didemethylthiocolchicines, in contrast to 2‐ O ‐acetyl‐, 2‐ O ,3‐ O ‐diacetyl‐ and 3‐ O ‐acetyl analogs, showed after standing in CHCl 3 solution significant changes in optical rotation, a duplication of 1 H‐NMR signals, and the formation of new isomers on TLC. Solid‐state X‐ray diffraction of O ‐acetylated colchinoids and thio analogs, showed out of planar arrangements of the aromatic substituents, but the analysis could not help to explain the structures of the newly formed isomers in CHCl 3 solution.