Synthese von spirocyclischen Isothiazoliumsalzen und deren basenkatalysierte Umsetzung zu Thianthrenen
摘要:
N-Phenyl-substituted isothiazolium salts 1 with active 7-methylene group react under the influence of bases to the spirocyclic isothiazolium salts raccis- and rac-trans-4; the salts trans-4 are not stable and react to the thianthrene derivatives rac-trans-6. Thus, a very simple separation of diastereoisomeric salts rac-cis- and rac-trans-4 is possible. The influence of donor and acceptor substituents in the phenyl group of 1 on the diastereoselective synthesis of 4 and 6 was studied. The structure of rac-cis-4 and rac-trans-6 was confirmed by X-ray analysis.