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Demethyl(trifluoromethyl)actinomycins, II . Bis(trifluoromethylated) 4‐(2′‐Benzoxazolyl)actinocin Derivatives
Author(s) -
Bahner Isabel,
Lackner Helmut
Publication year - 1997
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199719970531
Subject(s) - chemistry , trifluoromethyl , trimer , yield (engineering) , derivative (finance) , medicinal chemistry , stereochemistry , condensation , quinone , organic chemistry , dimer , alkyl , materials science , physics , economics , financial economics , metallurgy , thermodynamics
In a previous study, performed in connection with the total synthesis of trifluoromethylated actinocinyl peptides 2a , the oxidative condensation of the corresponding o ‐aminophenol precursor 1 furnished a novel trimerisation product, which had been tentatively assigned to the triphenedioxazine structure 3 [1] . Now, an improved synthesis of the trimer and extensive 1‐ and 2D‐NMR studies have resulted in a new, quite unexpected structure: the 4‐(2′‐benzoxazolyl)actinocin derivative 8a , which replaces 3 . Apparently, the quinone‐sided CF 3 group of an actinocin intermediate is unusually activated and reacts with a third o ‐aminophenol unit. The modifications to the synthesis increase the overall yield of demethyl‐(trifluoromethyl)actinomycins by a factor of five.