5-t-Butyl-1,2-thiazinylium 6c and rigid 5,8-ethano-5,8-dihydrobenzo[d]-1,2-
thiazinylium salts 17 without conjugated stabilization with the aromatic ri
ng at the 4- or 5-position of the thiazine ring have been successfully obta
ined as crystals. (C) 2001 Elsevier Science Ltd. Air rights reserved.