Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... 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 ring at the 4- or 5-position of the thiazine ring have been successfully obtained as crystals. ... The novel 5-t-butyl (1) and ...