1,2-Thiazines and related heterocycles. Part 2. Synthesis and characterisation of the cycloadducts of N-sulphinylanilines and 1,4-epoxy-1,4-dihydro-naphthalenes. Derivatives of 5H-6-thia-5-azabenz[a]anthracene 6-oxide

Abstract

Cycloaddition of N-sulphinylanilines to 1,4-epoxy-1,4-dihydronaphthalenes yields 7,12-epoxy-6a,7,12,12a-tetrahydro-5H-6-thia-5-azabenz[a]anthracene 6-oxides. Positional isomerism may arise in the adducts from unsymmetrical substitution in the reactants; diastereoisomerism occurs owing to the chirality created at sulphur by the cycloaddition. The structures and isomeric preferences of the various adducts are elucidated and their reactions to give the title heterocycles and other products are described.