Zwitterionic surfactant compounds provide effective therapy for ulceration of the gastric mucosa. The tendency of . aspirin and other salicylate-based drugs to cause ulceration of the gastric mucosa is also reduced by administration of such drugs in conjunction with certain zwitterionic surfactants. The ammoniohexanoate zwitterionics are especially preferred in the management of both gastric and duodenal ulcers.
Stabilization of ortho-quinone methides by a bis(sulfonium ylide) derived from 2,5-dihydroxy-[1,4]benzoquinone
作者:Anjan Patel、Thomas Netscher、Thomas Rosenau
DOI:10.1016/j.tetlet.2008.02.045
日期:2008.4
The zwitterionic intermediates (2a) in the oxidation of ortho-alkylphenols (1) and bis(sulfoniumylide) 3 form reasonably stable 2:1-complexes (4), in which the ortho-quinone methide (oQM) moieties are not present in quinoid form with the exocyclic in-plane methylene group, but as zwitterionic, aromatic conformer having an out-of-plane exocyclic methylene group. The complex 7 derived from the α-tocopherol