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Aromatic Sulfonation, 130 . – Relative Intramolecular Reactivity of the Insulated π Double Bond and the 14π Annulene Perimeter toward Sulfur Trioxide in the Sulfonation of Isopyrenes
Author(s) -
Cerfontain Hans,
Bakker Bert H.,
KoebergTelder Ankie,
Wilmes Oswald
Publication year - 1996
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.199719970110
Subject(s) - chemistry , annulene , dichloromethane , sulfur trioxide , medicinal chemistry , electrophile , reactivity (psychology) , sulfonate , intramolecular force , nucleophile , dimethyl sulfoxide , solvent , organic chemistry , polymer chemistry , catalysis , sulfuric acid , sodium , medicine , alternative medicine , pathology
The sulfonation of isopyrene ( 1 ) and its 5‐methyl‐ and 5,10‐dimethyl derivative 2 and 3 with SO 3 in both dichloromethane and nitromethane as solvent has been studied. Reaction of 1 and 2 leads to sulfodehydrogenation in which SO 3 reacts as a monodentate electrophile, the initial products being 1 ‐5‐sulfonic acid ( 1 ‐5‐S) and 2 ‐10‐S, respectively. In the presence of a sufficiently large amount of SO 3 1 ‐5‐S is subsequently converted into 1 ‐5,10‐S 2 . With 3 , using 2.0 molequiv, of the sulfonating reagent in dichloromethane, the SO 3 adds as a bidentate electrophile to the “central C=C bond” with formation of 7,14‐dimethyl‐1,6:8,13‐ethanediylidene‐[14]annulene‐15,16‐sultone ( 5 ) and the corresponding pyrosultone 6 . Upon subsequent hydrolysis and neutralization with aqueous KOH the eventually obtained product is potasium 16‐hydroxy‐7,14‐dimethyl‐1,6:8,13‐ethanediylidene‐[14]annulene‐15‐sulfonate ( 4 ).